history of microsoft windows

this blog is for educational purpose only
to help some student for researching.

1975–1981: Microsoft boots up

Microsoft co-founders Paul Allen (left) and Bill Gates
future and past photo

It’s the 1970s. At work, we rely on typewriters. If we need to copy a document, we likely use a mimeograph or carbon paper. Few have heard of microcomputers, but two young computer enthusiasts, Bill Gates and Paul Allen, see that personal computing is a path to the future.

In 1975, Gates and Allen form a partnership called Microsoft. Like most start-ups, Microsoft begins small, but has a huge vision—a computer on every desktop and in every home. During the next years, Microsoft begins to change the ways we work.

The dawn of MS‑DOS

In June 1980, Gates and Allen hire Gates’ former Harvard classmate Steve Ballmer to help run the company. The next month, IBM approaches Microsoft about a project code-named "Chess." In response, Microsoft focuses on a new operating system—the software that manages, or runs, the computer hardware and also serves to bridge the gap between the computer hardware and programs, such as a word processor. It’s the foundation on which computer programs can run. They name their new operating system "MS‑DOS."

When the IBM PC running MS‑DOS ships in 1981, it introduces a whole new language to the general public. Typing “C:” and various cryptic commands gradually becomes part of daily work. People discover the backslash (\) key.

MS‑DOS is effective, but also proves difficult to understand for many people. There has to be a better way to build an operating system.

Geek trivia: MS‑DOS stands for Microsoft Disk Operating System.

1982–1985: Introducing Windows 1.0

The Windows 1.0 desktop

The fully-packaged Windows 1.0

Microsoft works on the first version of a new operating system. Interface Manager is the code name and is considered as the final name, but Windows prevails because it best describes the boxes or computing “windows” that are fundamental to the new system. Windows is announced in 1983, but it takes a while to develop. Skeptics call it “vaporware.”

On November 20, 1985, two years after the initial announcement, Microsoft ships Windows 1.0. Now, rather than typing MS‑DOS commands, you just move a mouse to point and click your way through screens, or “windows.” Bill Gates says, “It is unique software designed for the serious PC user.”

There are drop-down menus, scroll bars, icons, and dialog boxes that make programs easier to learn and use. You're able to switch among several programs without having to quit and restart each one. Windows 1.0 ships with several programs, including MS‑DOS file management, Paint, Windows Writer, Notepad, Calculator, and a calendar, card file, and clock to help you manage day-to-day activities. There’s even a game—Reversi.

Geek trivia: Remember floppy disks and kilobytes? Windows 1.0 requires a minimum of 256 kilobytes (KB), two double-sided floppy disk drives, and a graphics adapter card. A hard disk and 512 KB memory is recommended for running multiple programs or when using DOS 3.0 or higher.

The Windows 2.0 desktop

Windows 2.0

On December 9, 1987 Microsoft releases Windows 2.0 with desktop icons and expanded memory. With improved graphics support, you can now overlap windows, control the screen layout, and use keyboard shortcuts to speed up your work. Some software developers write their first Windows–based programs for this release.

Windows 2.0 is designed for the Intel 286 processor. When the Intel 386 processor is released, Windows/386 soon follows to take advantage of its extended memory capabilities. Subsequent Windows releases continue to improve the speed, reliability, and usability of the PC.

In 1988, Microsoft becomes the world’s largest PC software company based on sales. Computers are starting to become a part of daily life for some office workers.

Geek trivia: Control Panel makes its first appearance in Windows 2.0.

Windows 1 and Windows 2

The first independent version of Microsoft Windows, version 1.0, released on 20 November 1985, achieved little popularity. It was originally going to be called "Interface Manager" but Rowland Hanson, the head of marketing at Microsoft, convinced the company that the name Windows would be more appealing to customers.

Windows 1.0 was not a complete operating system, but rather an "operating environment" that extended MS-DOS, and shared the latter's inherent flaws and problems.

The first version of Microsoft Windows included a simple graphics painting program called Windows Paint; Windows Write, a simple word processor; an appointment calendar; a card-filer; a notepad; a clock; a control panel; a computer terminal;Clipboard; and RAM driver. It also included the MS-DOS Executive and a game called Reversi.

Microsoft had worked with Apple Computer to develop applications for Apple's new Macintosh computer, which featured agraphical user interface. As part of the related business negotiations, Microsoft had licensed certain aspects of the Macintosh user interface from Apple; in later litigation, a district court summarized these aspects as "screen displays". In the development of Windows 1.0, Microsoft intentionally limited its borrowing of certain GUI elements from the Macintosh user interface, to comply with its license.

For example, windows were only displayed "tiled" on the screen; that is, they could not overlap or overlie one another.

Microsoft Windows version 2 came out on 9 December 1987, and proved slightly more popular than its predecessor. Much of the popularity for Windows 2.0 came by way of its inclusion as a "run-time version" with Microsoft's new graphical applications,Excel and Word for Windows. They could be run from MS-DOS, executing Windows for the duration of their activity, and closing down Windows upon exit.

Microsoft Windows received a major boost around this time when Aldus PageMaker appeared in a Windows version, having previously run only on Macintosh. Some computer historians^[who?] date this, the first appearance of a significant and non-Microsoft application for Windows, as the start of the success of Windows.

Versions 2.0x used the real-mode memory model, which confined it to a maximum of 1 megabyte of memory. In such a configuration, it could run under another multitasker like DESQview, which used the 286 protected mode.

Later, two new versions were released: Windows/286 2.1 and Windows/386 2.1. Like prior versions of Windows, Windows/286 2.1 used the real-mode memory model, but was the first version to support the High Memory Area. Windows/386 2.1 had a protected mode kernel with LIM-standard EMS emulation, the predecessor to XMS which would finally change the topology of IBM PC computing. All Windows and DOS-based applications at the time were real mode, running over the protected mode kernel by using the virtual 8086 mode, which was new with the 80386 processor.

Version 2.03, and later 3.0, faced challenges from Apple over its overlapping windows and other features Apple charged mimicked the ostensibly copyrighted "look and feel" of its operating system and "embodie[d] and generated a copy of the Macintosh" in its OS. Judge William Schwarzer dropped all but 10 of Apple's 189 claims of copyright infringement, and ruled that most of the remaining 10 were over uncopyrightable ideas.

1990–1994: Windows 3.0–Windows NT—Getting the graphics

The Windows 3.0 desktop

Bill Gates shows the newly-released Windows 3.0

Windows 3.0

On May 22, 1990, Microsoft announces Windows 3.0, followed shortly by Windows 3.1 in 1992. Taken together, they sell 10 million copies in their first two years, making this the most widely used Windows operating system yet. The scale of this success causes Microsoft to revise earlier plans. Virtual Memory improves visual graphics. In 1990 Windows starts to look like the versions to come.

Windows now has significantly better performance, advanced graphics with 16 colors, and improved icons. A new wave of 386 PCs helps drive the popularity of Windows 3.0. With full support for the Intel 386 processor, programs run noticeably faster. Program Manager, File Manager, and Print Manager arrive in Windows 3.0.

Windows software is installed with floppy discs bought in large boxes with heavy instruction manuals.

The popularity of Windows 3.0 grows with the release of a new Windows software development kit (SDK), which helps software developers focus more on writing programs and less on writing device drivers.

Windows is increasingly used at work and home and now includes games like Solitaire, Hearts, and Minesweeper. An advertisement: “Now you can use the incredible power of Windows 3.0 to goof off.”

Windows for Workgroups 3.11 adds peer-to-peer workgroup and domain networking support and, for the first time, PCs become an integral part of the emerging client/server computing evolution.

Windows NT

When Windows NT releases on July 27, 1993, Microsoft meets an important milestone: the completion of a project begun in the late 1980s to build an advanced new operating system from scratch. "Windows NT represents nothing less than a fundamental change in the way that companies can address their business computing requirements," Bill Gates says at its release.

Unlike Windows 3.1, however, Windows NT 3.1 is a 32-bit operating system, which makes it a strategic business platform that supports high-end engineering and scientific programs.

Geek trivia: The group that develops Windows NT was originally called the "Portable Systems" team.

Success with Windows 3.0

Microsoft Windows scored a significant success with Windows 3.0, released in May 1990. In addition to improved capabilities given to native applications, Windows also allowed users to better multitask older MS-DOS based software compared to Windows/386, thanks to the introduction of virtual memory.

Windows 3.0's user interface finally resembled a serious competitor to the user interface of the Macintosh computer. PCs had improved graphics by this time, due to VGA video cards, and the protected/enhanced mode allowed Windows applications to use more memory in a more painless manner than their DOS counterparts could. Windows 3.0 could run in real, standard, or 386 enhanced modes, and was compatible with any Intel processor from the 8086/8088 up to the 80286 and 80386. This was the first version to run Windows programs in protected mode, although the 386 enhanced mode kernel was an enhanced version of the protected mode kernel in Windows/386.

A "multimedia" version, Windows 3.0 with Multimedia Extensions 1.0, was released in October 1991. This was bundled with "multimedia upgrade kits", comprising a CD-ROM drive and a sound card, such as the Creative Labs Sound Blaster Pro. This version was the precursor to the multimedia features available in Windows 3.1 and later, and was part of Microsoft's specification for the Multimedia PC.

The features listed above and growing market support from application software developers made Windows 3.0 wildly successful, selling around 10 million copies in the two years before the release of version 3.1. Windows 3.0 became a major source of income for Microsoft, and led the company to revise some of its earlier plans. It was discontinued on 31 December 2001.

A step sideways: OS/2

OS/2 logo

During the mid to late 1980s, Microsoft and IBM had cooperatively been developingOS/2 as a successor to DOS. OS/2 would take full advantage of the aforementioned protected mode of the Intel 80286 processor and up to 16 MB of memory. OS/2 1.0, released in 1987, supported swapping and multitasking and allowed running of DOSexecutables.

A GUI, called the Presentation Manager (PM), was not available with OS/2 until version 1.1, released in 1988. Its API was incompatible with Windows. Version 1.2, released in 1989, introduced a new file system, HPFS, to replace the FAT file system.

By the early 1990s, conflicts developed in the Microsoft/IBM relationship. They cooperated with each other in developing their PC operating systems, and had access to each other's code. Microsoft wanted to further develop Windows, while IBM desired for future work to be based on OS/2. In an attempt to resolve this tension, IBM and Microsoft agreed that IBM would develop OS/2 2.0, to replace OS/2 1.3 and Windows 3.0, while Microsoft would develop a new operating system, OS/2 3.0, to later succeed OS/2 2.0.

This agreement soon however fell apart, and the Microsoft/IBM relationship was terminated. IBM continued to develop OS/2, while Microsoft changed the name of its (as yet unreleased) OS/2 3.0 to Windows NT. Both retained the rights to use OS/2 and Windows technology developed up to the termination of the agreement; Windows NT, however, was to be written anew, mostly independently (see below).

After an interim 1.3 version to fix up many remaining problems with the 1.x series, IBM released OS/2 version 2.0 in 1992. This was a major improvement: it featured a new, object-oriented GUI, the Workplace Shell (WPS), that included a desktop and was considered by many to be OS/2's best feature. Microsoft would later imitate much of it in Windows 95. Version 2.0 also provided a full 32-bit API, offered smooth multitasking and could take advantage of the 4 gigabytes of address space provided by the Intel 80386. Still, much of the system had 16-bit code internally which required, among other things, device drivers to be 16-bit code also. This was one of the reasons for the chronic shortage of OS/2 drivers for the latest devices. Version 2.0 could also run DOS and Windows 3.0 programs, since IBM had retained the right to use the DOS and Windows code as a result of the breakup.

Windows 3.1 and NT 3.x

In response to the impending release of OS/2 2.0, Microsoft developed Windows 3.1, which included several minor improvements to Windows 3.0 (such as display of TrueType scalable fonts, developed jointly with Apple), but primarily consisted of bugfixes and multimedia support. It also excluded support for Real mode, and only ran on an 80286 or better processor. Later Microsoft also released Windows 3.11, a touch-up to Windows 3.1 which included all of the patches and updates that followed the release of Windows 3.1 in 1992. Around the same time, Microsoft released Windows for Workgroups (WfW), which was available both as an add-on for existing Windows 3.1 installations and in a version that included the base Windows environment and the networking extensions all in one package. Windows for Workgroups included improved network drivers and protocol stacks, and support for peer-to-peer networking. One optional download for WfW was the "Wolverine" TCP/IP protocol stack, which allowed for easy access to the Internet through corporate networks. There were two versions of Windows for Workgroups, WfW 3.1 and WfW 3.11. Unlike prior versions, Windows for Workgroups 3.11 ran in 386 enhanced mode only, and needs at least an 80386SX processor.

All these versions continued version 3.0's impressive sales pace. Even though the 3.1x series still lacked most of the important features of OS/2, such as long file names, a desktop, or protection of the system against misbehaving applications, Microsoft quickly took over the OS and GUI markets for the IBM PC. The Windows API became the de facto standard for consumer software.

Meanwhile, Microsoft continued to develop Windows NT. The main architect of the system was Dave Cutler, one of the chief architects of VMS at Digital Equipment Corporation (later acquired by Compaq, now part of Hewlett-Packard).^[5] Microsoft hired him in August 1988 to create a successor to OS/2, but Cutler created a completely new system instead. Cutler had been developing a follow-on to VMS at DEC called Mica, and when DEC dropped the project he brought the expertise and around 20 engineers with him to Microsoft. DEC also believed he brought Mica's code to Microsoft and sued.^[6] Microsoft eventually paid US$150 million and agreed to support DEC's Alpha CPU chip in NT.

Windows NT 3.1 (Microsoft marketing wanted Windows NT to appear to be a continuation of Windows 3.1) arrived in Beta form to developers at the July 1992 Professional Developers Conference in San Francisco.^[7] Microsoft announced at the conference its intentions to develop a successor to both Windows NT and Windows 3.1's replacement (Windows 95, codenamed Chicago), which would unify the two into one operating system. This successor was codenamed Cairo. In hindsight, Cairo was a much more difficult project than Microsoft had anticipated and, as a result, NT and Chicago would not be unified until Windows XP—albeit Windows 2000, oriented to business, had already unified most of the system’s bolts and gears, it was XP that was sold to home consumers like Windows 95 and came to be viewed as the final unified OS. Parts of Cairo have still not made it into Windows as of 2009 - specifically, the WinFS file system, which was the much touted Object File System of Cairo. Microsoft announced that they have discontinued the separate release of WinFS for Windows XP and Windows Vista^[8] and will gradually incorporate the technologies developed for WinFS in other products and technologies, notably Microsoft SQL Server.

Driver support was lacking due to the increased programming difficulty in dealing with NT's superior hardware abstraction model. This problem plagued the NT line all the way through Windows 2000. Programmers complained that it was too hard to write drivers for NT, and hardware developers were not going to go through the trouble of developing drivers for a small segment of the market. Additionally, although allowing for good performance and fuller exploitation of system resources, it was also resource-intensive on limited hardware, and thus was only suitable for larger, more expensive machines.

However, these same features made Windows NT perfect for the LAN server market (which in 1993 was experiencing a rapid boom, as office networking was becoming common). NT also had advanced network connectivity options and NTFS, an efficient file system. Windows NT version 3.51 was Microsoft's entry into this field, and took away market share from Novell (the dominant player) in the following years.

One of Microsoft's biggest advances initially developed for Windows NT was a new 32-bit API, to replace the legacy 16-bitWindows API. This API was called Win32, and from then on Microsoft referred to the older 16-bit API as Win16. The Win32 API had three main implementations: one for Windows NT, one for Win32s (which was a subset of Win32 which could be used on Windows 3.1 systems), and one for Chicago. Thus Microsoft sought to ensure some degree of compatibility between the Chicago design and Windows NT, even though the two systems had radically different internal architectures. Windows NT was the first Windows operating system based on a hybrid kernel.

1995–1998: Windows 95—the PC comes of age (and don't forget the Internet)

The Windows 95 desktop

Launch day: Bill Gates introduces Windows 95

Windows 95

On August 24, 1995, Microsoft releases Windows 95, selling a record-setting 7 million copies in the first five weeks. It’s the most publicized launch Microsoft has ever taken on. Television commercials feature the Rolling Stones singing "Start Me Up" over images of the new Start button. The press release simply begins: “It’s here.”

This is the era of fax/modems, email, the new online world, and dazzling multimedia games and educational software. Windows 95 has built-in Internet support, dial-up networking, and new Plug and Play capabilities that make it easy to install hardware and software. The 32-bit operating system also offers enhanced multimedia capabilities, more powerful features for mobile computing, and integrated networking.

At the time of the Windows 95 release, the previous Windows and MS–DOS operating systems are running on about 80 percent of the world’s PCs. Windows 95 is the upgrade to these operating systems. To run Windows 95, you need a PC with a 386DX or higher processor (486 recommended) and at least 4 MB of RAM (8 MB of RAM recommended). Upgrade versions are available for both floppy disk and CD-ROM formats. It’s available in 12 languages.

Windows 95 features the first appearance of the Start menu, taskbar, and minimize, maximize, and close buttons on each window.

Catching the Internet wave

In the early 1990s, tech insiders are talking about the Internet—a network of networks that has the power to connect computers all over the world. In 1995, Bill Gates delivers a memo titled “The Internet Tidal Wave,” and declares the Internet as “the most important development since the advent of the PC.”

In the summer of 1995, the first version of Internet Explorer is released. The browser joins those already vying for space on the World Wide Web.

Geek trivia: In 1996, Microsoft releases Flight Simulator for Windows 95—the first time in its 14-year history that it’s available for Windows.

Windows 95

After Windows 3.11, Microsoft began to develop a new consumer oriented version of the operating system codenamed Chicago. Chicago was designed to have support for 32-bit preemptive multitasking like OS/2 and Windows NT, although a 16-bit kernel would remain for the sake of backward compatibility. The Win32 API first introduced with Windows NT was adopted as the standard 32-bit programming interface, with Win16 compatibility being preserved through a technique known as "thunking". A new object oriented GUI was not originally planned as part of the release, although elements of the Cairo user interface were borrowed and added as other aspects of the release (notably Plug and Play) slipped.

Microsoft did not change all of the Windows code to 32-bit; parts of it remained 16-bit (albeit not directly using real mode) for reasons of compatibility, performance, and development time. Additionally it was necessary to carry over design decisions from earlier versions of Windows for reasons of backwards compatibility, even if these design decisions no longer matched a more modern computing environment. These factors eventually began to impact the operating system's efficiency and stability.

Microsoft marketing adopted Windows 95 as the product name for Chicago when it was released on 24 August 1995. Microsoft had a double gain from its release: first, it made it impossible for consumers to run Windows 95 on a cheaper, non-Microsoft DOS; secondly, although traces of DOS were never completely removed from the system and MS DOS 7 would be loaded briefly as a part of the booting process, Windows 95 applications ran solely in 386 enhanced mode, with a flat 32-bit address space and virtual memory. These features make it possible for Win32 applications to address up to 2 gigabytes of virtual RAM (with another 2 GB reserved for the operating system), and in theory prevented them from inadvertently corrupting the memory space of other Win32 applications. In this respect the functionality of Windows 95 moved closer to Windows NT, although Windows 95/98/ME did not support more than 512 megabytes of physical RAM without obscure system tweaks.

IBM continued to market OS/2, producing later versions in OS/2 3.0 and 4.0 (also called Warp). Responding to complaints about OS/2 2.0's high demands on computer hardware, version 3.0 was significantly optimized both for speed and size. Before Windows 95 was released, OS/2 Warp 3.0 was even shipped preinstalled with several large German hardware vendor chains. However, with the release of Windows 95, OS/2 began to lose market share.

It is probably impossible to choose one specific reason why OS/2 failed to gain much market share. While OS/2 continued to run Windows 3.1 applications, it lacked support for anything but the Win32s subset of Win32 API (see above). Unlike with Windows 3.1, IBM did not have access to the source code for Windows 95 and was unwilling to commit the time and resources to emulate the moving target of the Win32 API. IBM later introduced OS/2 into the United States v. Microsoft case, blaming unfair marketing tactics on Microsoft's part.

Microsoft went on to release five different versions of Windows 95:

• Windows 95 - original release
• Windows 95 A - included Windows 95 OSR1 slipstreamed into the installation.
• Windows 95 B - (OSR2) included several major enhancements, Internet Explorer (IE) 3.0 and full FAT32 file system support.
• Windows 95 B USB - (OSR2.1) included basic USB support.
• Windows 95 C - (OSR2.5) included all the above features, plus IE 4.0. This was the last 95 version produced.

OSR2, OSR2.1, and OSR2.5 were not released to the general public; rather, they were available only to OEMs that would preload the OS onto computers. Some companies sold new hard drives with OSR2 preinstalled (officially justifying this as needed due to the hard drive's capacity).

The first Microsoft Plus! add-on pack was sold for Windows 95.

1998–2000: Windows 98, Windows 2000, Windows Me—Windows evolves for work and play

Windows 98

The Windows 98 desktop

Windows 2000 Professional

The Windows Me media experience

Windows 98

Released on June 25, 1998, Windows 98 is the first version of Windows designed specifically for consumers. PCs are common at work and home, and Internet cafes where you can get online are popping up. Windows 98 is described as an operating system that “Works Better, Plays Better.”

With Windows 98, you can find information more easily on your PC as well as the Internet. Other improvements include the ability to open and close programs more quickly, and support for reading DVD discs and universal serial bus (USB) devices. Another first appearance is the Quick Launch bar, which lets you run programs without having to browse the Start menu or look for them on the desktop.

Geek trivia: Windows 98 is the last version based on MS‑DOS.

Windows Me

Designed for home computer use, Windows Me offers numerous music, video, and home networking enhancements and reliability improvements compared to previous versions.

First appearances: System Restore, a feature that can roll back your PC software configuration to a date or time before a problem occurred. Movie Maker provides users with the tools to digitally edit, save, and share home videos. And with Microsoft Windows Media Player 7 technologies, you can find, organize, and play digital media.

Geek trivia: Technically speaking, Windows Me was the last Microsoft operating system to be based on the Windows 95 code base. Microsoft announced that all future operating system products would be based on the Windows NT and Windows 2000 kernel.

Windows 2000 Professional

More than just the upgrade to Windows NT Workstation 4.0, Windows 2000 Professional is designed to replace Windows 95, Windows 98, and Windows NT Workstation 4.0 on all business desktops and laptops. Built on top of the proven Windows NT Workstation 4.0 code base, Windows 2000 adds major improvements in reliability, ease of use, Internet compatibility, and support for mobile computing.

Among other improvements, Windows 2000 Professional simplifies hardware installation by adding support for a wide variety of new Plug and Play hardware, including advanced networking and wireless products, USB devices, IEEE 1394 devices, and infrared devices.

Geek trivia: The nightly stress test performed on Windows 2000 during development is the equivalent of three months of run time on up to 1,500 computers.

Windows 98

On 25 June 1998, Microsoft released Windows 98 (codenamed Memphis). It included new hardware drivers and the FAT32file system which supports disk partitions that are larger than 2 GB (first introduced in Windows 95 OSR2). USB support in Windows 98 is marketed as a vast improvement over Windows 95. The release continued the controversial inclusion of theInternet Explorer browser with the operating system that started with Windows 95 OEM Service Release 1. The action eventually led to the filing of the United States v. Microsoft case, dealing with the question of whether Microsoft was introducing unfair practices into the market in an effort to eliminate competition from other companies such as Netscape.^[10]

In 1999, Microsoft released Windows 98 Second Edition, an interim release. One of the more notable new features was the addition of Internet Connection Sharing, a form of network address translation, allowing several machines on a LAN (Local Area Network) to share a single Internet connection. Hardware support through device drivers was increased. Many minor problems that existed in the first edition were fixed making it, according to many, the most stable release of the Windows 9xfamily.

Windows 2000

Microsoft released Windows 2000 in February 2000. It has the version number Windows NT 5.0. It was successfully deployed both on the server and the workstation markets. Amongst Windows 2000's most significant new features was Active Directory, a near-complete replacement of the NT 4.0 Windows Server domain model, which built on industry-standard technologies likeDNS, LDAP, and Kerberos to connect machines to one another. Terminal Services, previously only available as a separate edition of NT 4, was expanded to all server versions. A number of features from Windows 98 were incorporated also, such as an improved Device Manager, Windows Media Player, and a revised DirectX that made it possible for the first time for many modern games to work on the NT kernel. Windows 2000 is also the last NT-kernel Windows operating system to lack product activation.

While Windows 2000 upgrades were available for Windows 95 and Windows 98, it was not intended for home users.^[11]

Windows 2000 was available in four editions:

• Windows 2000 Professional
• Windows 2000 Server
• Windows 2000 Advanced Server
• Windows 2000 Datacenter Server

Windows NT 4.0

Windows NT 4.0 was the successor of 3.51 (1995) and 3.5 (1994). Microsoft released Windows NT 4.0 to manufacturing in July 1996, one year after the release of Windows 95. Major new features included the new Explorer shell from Windows 95, scalability and feature improvements to the core architecture, kernel, USER32, COM and MSRPC.^[9]

Windows NT 4.0 came in four versions:

• Windows NT 4.0 Workstation
• Windows NT 4.0 Server
• Windows NT 4.0 Server, Enterprise Edition (includes support for 8-way SMP and clustering)
• Windows NT 4.0 Terminal Server

Windows ME

In September 2000, Microsoft released a successor to Windows 98 called Windows ME, short for "Millennium Edition". It was the last DOS-based operating system from Microsoft. Windows ME introduced a new multimedia-editing application calledWindows Movie Maker, came standard with Internet Explorer 5.5 and Windows Media Player 7, and debuted the first version of System Restore – a recovery utility that enables the operating system to revert system files back to a prior date and time. System Restore was a notable feature that would continue to thrive in later versions of Windows, including XP, Vista, and Windows 7.

Windows ME was conceived as a quick one-year project that served as a stopgap release between Windows 98 and Windows XP. Many of the new features were available from the Windows Update site as updates for older Windows versions (System Restore and Windows Movie Maker were exceptions). Windows ME was criticized for stability issues, and for lacking real mode DOS support, to the point of being referred to as the "Mistake Edition"^[12] or "Many Errors." Windows ME was the last operating system to be based on the Windows 9x (monolithic) kernel and MS-DOS.

2001–2005: Windows XP—Stable, usable, and fast

Windows XP Professional box

The Windows XP Home Edition desktop

On October 25, 2001, Windows XP is released with a redesigned look and feel that's centered on usability and a unified Help and Support services center. It’s available in 25 languages. From the mid-1970s until the release of Windows XP, about 1 billion PCs have been shipped worldwide.

For Microsoft, Windows XP will become one of its best-selling products in the coming years. It’s both fast and stable. Navigating the Start menu, taskbar, and Control Panel are more intuitive. Awareness of computer viruses and hackers increases, but fears are to a certain extent calmed by the online delivery of security updates. Consumers begin to understand warnings about suspicious attachments and viruses. There’s more emphasis on Help and Support.

Windows XP Home Edition offers a clean, simplified visual design that makes frequently used features more accessible. Designed for home use, Windows XP offers such enhancements as the Network Setup Wizard, Windows Media Player, Windows Movie Maker, and enhanced digital photo capabilities.

Windows XP Professional brings the solid foundation of Windows 2000 to the PC desktop, enhancing reliability, security, and performance. With a fresh visual design, Windows XP Professional includes features for business and advanced home computing, including remote desktop support, an encrypting file system, and system restore and advanced networking features. Key enhancements for mobile users include wireless 802.1x networking support, Windows Messenger, and Remote Assistance.

Windows XP has several editions during these years:

• Windows XP 64-bit Edition (2001) is the first Microsoft operating system for 64-bit processors designed for working with large amounts of memory and projects such as movie special effects, 3D animations, engineering, and scientific programs.
• Windows XP Media Center Edition (2002) is made for home computing and entertainment. You can browse the Internet, watch live television, enjoy digital music and video collections, and watch DVDs.
• Windows XP Tablet PC Edition (2002) realizes the vision of pen-based computing. Tablet PCs include a digital pen for handwriting recognition and you can use the mouse or keyboard, too.

Geek trivia: Windows XP is compiled from 45 million lines of code.

Windows XP

On 25 August 2001, Microsoft released Windows XP (codenamed "Whistler"). The merging of the Windows NT/2000 and Windows 95/98/Me lines was finally achieved with Windows XP. Windows XP uses the Windows NT 5.1 kernel, marking the entrance of the Windows NT core to the consumer market, to replace the aging 16/32-bit branch. The initial release met with considerable criticism, particularly in the area of security, leading to the release of three major Service Packs. Windows XP SP1 was released in September 2002, SP2 came out in August 2004 and SP3 came out in April 2008. Service Pack 2 provided significant improvements and encouraged widespread adoption of XP among both home and business users. Windows XP lasted longer as Microsoft's flagship operating system than any other version of Windows, from 25 October 2001 to 30 January 2007 when it was succeeded by Windows Vista.

Windows XP is available in a number of versions:

• Windows XP Home Edition, for home desktops and laptops - lacked features such as joining Active Directory Domain,Remote Desktop Server and Internet Information Services Server.
  • Windows XP Home Edition N, as above, but without a default installation of Windows Media Player, as mandated by aEuropean Union ruling
• Windows XP Professional, for business and power users contained all features in Home Edition.
  • Windows XP Professional N, as above, but without a default installation of Windows Media Player, as mandated by a European Union ruling
• Windows XP Media Center Edition (MCE), released in October 2002 for desktops and notebooks with an emphasis on home entertainment. Contained all features offered in Windows XP Professional and the Windows Media Center. Subsequent versions are the same but have an updated Windows Media Center.
  • Windows XP Media Center Edition 2003
  • Windows XP Media Center Edition 2004
  • Windows XP Media Center Edition 2005, released on 12 October 2004. Included Windows XP Service Pack 2, the Royale Windows Theme and joining a Windows Active Directory Domain is disabled. The Aquarium, Da Vinci, Nature and Space themes are retained from Windows XP Plus!
• Windows XP Tablet PC Edition, for tablet PCs
  • Windows XP Tablet PC Edition 2005
• Windows XP Embedded, for embedded systems
• Windows XP Starter Edition, for new computer users in developing countries
• Windows XP Professional x64 Edition, released on 25 April 2005 for home and workstation systems utilizing 64-bit processors based on the x86-64 instruction set developed by AMD as AMD64; Intel calls their version Intel 64
• Windows XP 64-bit Edition, is a version for Intel's Itanium line of processors; maintains 32-bit compatibility solely through a software emulator. It is roughly analogous to Windows XP Professional in features. It was discontinued in September 2005 when the last vendor of Itanium workstations stopped shipping Itanium systems marketed as "Workstations".
  • Windows XP 64-bit Edition 2003, based on the Windows NT 5.2 codebase.

Windows Server 2003

Windows Server 2003 Standard Edition cover box

Manage Your Server

Screenshot of Windows Server 2003 Enterprise

Windows Server 2003 (sometimes referred to as Win2K3) is a serveroperating system produced by Microsoft, released on April 24, 2003.An updated version, Windows Server 2003 R2, was released to manufacturing on December 6, 2005. Its successor, Windows Server 2008, was released on February 4, 2008. It is based on Windows XP, basically becoming an enhanced version of XP. According to Microsoft, Windows Server 2003 is more scalable and delivers better performance than its predecessor, Windows 2000.Windows Vista, as shipped, was developed based solely on Windows Server 2003 source code.

Overview

Windows Server 2003 was the follow-up to Windows 2000 Server, incorporating compatibility and other features fromWindows XP. Unlike Windows 2000 Server, Windows Server 2003's default installation has none of the server components enabled, to reduce the attack surface of new machines. Windows Server 2003 includes compatibility modes to allow older applications to run with greater stability. It was made more compatible with Windows NT 4.0 domain-based networking. Incorporating and upgrading a Windows NT 4.0 domain to Windows 2000 was considered difficult and time-consuming, and generally was considered an all-or-nothing upgrade, particularly when dealing with Active Directory.^[who?] Windows Server 2003 brought in enhanced Active Directory compatibility, and better deployment support, to ease the transition from Windows NT 4.0 to Windows Server 2003 and Windows XP Professional.

Changes to various services include those to the IIS web server, which was almost completely rewritten to improve performance and security, Distributed File System, which now supports hosting multiple DFS roots on a single server, Terminal Server, Active Directory, Print Server, and a number of other areas. Windows Server 2003 was also the first operating system released by Microsoft after the announcement of its Trustworthy Computing initiative, and as a result, contains a number of changes to security defaults and practices.

The product went through several name changes during the course of development. When first announced in 2000, it was known by its codename, "Whistler Server"; it was named "Windows 2002 Server" for a brief time in mid-2001 and then renamed "Windows .NET Server" and "Windows .NET Server 2003". According to Joe Wilcox of CNET News, these names were chosen in keeping with Microsoft .Net web service naming strategy. However, when Microsoft failed to communicate what exactly ".Net" represents, it dropped the branding and settled for "Windows Server 2003".

Development

Windows Server 2003 was the first Microsoft Windows version which was thoroughly subjected to semi-automated testing forbugs with a software system called PREfast developed by computer scientist Amitabh Srivastava at Microsoft Research.The automated bug checking system was first tested on Windows 2000 but not thoroughly.

Amitabh Srivastava's PREfast found 12% of Windows Server 2003's bugs, the remaining 88% being found by humancomputer programmers. Microsoft employs more than 4,700 programmers who work on Windows, 60% of which aresoftware testers whose job is to find bugs in Windows source code.

Microsoft co-founder Bill Gates stated that Windows Server 2003 was Microsoft's "most rigorously tested software to date."

Changes

The following features are new to Windows Server 2003:

• Internet Information Services (IIS) v6.0
• Significant improvements to Message Queuing
• Manage Your Server – a role management administrative tool that allows an administrator to choose what functionality the server should provide
• Improvements to Active Directory, such as the ability to deactivate classes from the schema, or to run multiple instances of the directory server (ADAM)
• Improvements to Group Policy handling and administration
• Provides a backup system to restore lost files
• Improved disk management, including the ability to back up from shadows of files, allowing the backup of open files.
• Improved scripting and command line tools, which are part of Microsoft's initiative to bring a complete command shell to the next version of Windows
• Support for a hardware-based "watchdog timer", which can restart the server if the operating system does not respond within a certain amount of time.

The ability to create rescue disk was removed in favor of Automated System Recovery (ASR).

Editions

Windows Server 2003 comes in a number of editions, each targeted towards a particular size and type of business. In general, all variants of Windows Server 2003 have the ability to share files and printers, act as an application server, host message queues, provide email services, authenticate users, act as an X.509 certificate server, provide LDAP directory services, serve streaming media, and to perform other server-oriented functions.

Supported hardware capabilities across editions of Windows Server 2003 CriteriaWebStandardEnterpriseDatacenterNumber of physical CPUs21–41–88–64Maximum supported RAMIA-322 GB4 GB64 GB64 GBx64N/A32 GB1 TB1 TBItaniumN/AN/A2 TB2 TB

Web

Windows Server 2003 Web is meant for building and hosting Web applications, Web pages, and XML web services. It is designed to be used primarily as an IIS 6.0 Web server and provides a platform for developing and deploying XML Web services and applications that use ASP.NET technology, a key part of the .NET Framework. Terminal Services is not included on Web Edition. However, Remote Desktop for Administration is available. Only 10 concurrent file-sharing connections are allowed at any moment. It is not possible to install Microsoft SQL Server and Microsoft Exchange software in this edition without installing Service Pack 1. Despite supporting XML Web services and ASP.NET, UDDI cannot be deployed on Windows Server 2003 Web. The .NET Framework version 2.0 is not included with Windows Server 2003 Web, but can be installed as a separate update from Windows Update.

Windows Server 2003 Web supports a maximum of 2 physical processors and a maximum of 2GB of RAM. However, an instance of Windows Server 2003 Web cannot act as a domain controller. It is the only edition of Windows Server 2003 that does not require Client Access Licenses when used as the internet facing server front-end for Internet Information Servicesand Windows Server Update Services. When using it for storage or as a back-end with another remote server as the front-end, CALs may still be required.

Standard

Microsoft Windows Server 2003 Standard is aimed towards small to medium sized businesses. Standard Edition supports file and printer sharing, offers secure Internet connectivity, and allows centralized desktop application deployment. A specialized version for the x64 architecture (AMD64 and EM64T, called collectively x64 by Microsoft) was released in April 2005.The IA-32 version supports up to 4 physical processors and up to 4 GB RAM; the x64 version is capable of addressing up to 32 GB of RAM and also supports Non-Uniform Memory Access.

Enterprise

Windows Server 2003 Enterprise is aimed towards medium to large businesses. It is a full-function server operating system that supports up to 8 physical processors and provides enterprise-class features such as eight-node clustering using Microsoft Cluster Server (MSCS) software and support for up to 64 GB of RAM through PAE (added with the /PAE boot string). Enterprise Edition also comes in specialized versions for the x64 and Itanium architectures. With Service Pack 2 installed, the x64 and Itanium versions are capable of addressing up to 1 TB and 2 TB of RAM, respectively. This edition also supports Non-Uniform Memory Access (NUMA). It also provides the ability to hot-add supported hardware. Windows Server 2003 Enterprise is also the required edition to issue custom certificate templates.

Updates

Service Pack 1

On March 30, 2005, Microsoft released Service Pack 1 for Windows Server 2003. Among the improvements are many of the same updates that were provided to Windows XP users with Service Pack 2. Features that are added with Service Pack 1 include:

• Security Configuration Wizard: A tool that allows administrators to more easily research, and make changes to, security policies.
• Hot Patching: This feature is set to extend Windows Server 2003's ability to take DLL, Driver, and non-kernel patches without a reboot.
• IIS 6.0 Metabase Auditing: Allowing the tracking of metabase edits.
• Windows Firewall: Brings many of the improvements from Windows XP Service Pack 2 to Windows Server 2003; also with the Security Configuration Wizard, it allows administrators to more easily manage the incoming open ports, as it will automatically detect and select default roles.
• Other networking improvements include support for Wireless Provisioning Services, better IPv6 support, and new protections against SYN flood TCP attacks.
• Post-Setup Security Updates: A default mode that is turned on when a Service Pack 1 server is first booted up after installation. It configures the firewall to block all incoming connections, and directs the user to install updates.
• Data Execution Prevention (DEP): Support for the No Execute (NX) bit which helps to prevent buffer overflow exploits that are often the attack vector of Windows Server exploits.
• Windows Media Player version 10
• Internet Explorer 6 SV1 (e.g. 'IE6 SP2')
• Support for fixed disks bearing data organized using the GUID Partition Table system

A full list of updates is available in the Microsoft Knowledge Base.

Service Pack 2[edit]

Service Pack 2 for Windows Server 2003 was released on March 13, 2007. The release date was originally scheduled for the first half of 2006.^[31] On June 13, 2006, Microsoft made an initial test version of Service Pack 2 available to Microsoft Connect users, with a build number of 2721. This was followed by build 2805, known as Beta 2 Refresh. The final build is 3790.

Microsoft has described Service Pack 2 as a "standard" service pack release containing previously released security updates, hotfixes, and reliability and performance improvements. In addition, Service Pack 2 contains Microsoft Management Console 3.0, Windows Deployment Services (which replaces Remote Installation Services), support for WPA2, and improvements to IPsec and MSConfig. Service Pack 2 also adds Windows Server 2003 Scalable Networking Pack (SNP),which allows hardware acceleration for processing network packets, thereby enabling faster throughput. SNP was previously available as an out-of-band update for Windows Server 2003 Service Pack 1.

As of October 2009, no further Service Packs are planned for Windows Server 2003.

Windows Server 2003 R2

Windows Server 2003 R2 is the successor of Windows Server 2003, released to manufacturing on December 6, 2005. It was released for x86 and x64 platforms, but not for IA-64. It is distributed on two CDs, with one CD being the Windows Server 2003 SP1 CD. The other CD adds many optionally installable features for Windows Server 2003 R2

New features

Branch Office Server Management

• Centralized management tools for file and printers
• Enhanced Distributed File System (DFS) namespace management interface
• More efficient WAN data replication with Remote Differential Compression.

Identity and Access Management

• Extranet Single Sign-On and identity federation
• Centralized administration of extranet application access
• Automated disabling of extranet access based on Active Directory account information
• User access logging
• Cross-platform web Single Sign-On and password synchronization using Network Information Service (NIS)

Storage Management

• File Server Resource Manager (storage utilization reporting)
• Enhanced quota management
• File screening limits files types allowed
• Storage Manager for Storage Area Networks (SAN) (storage array configuration)

Server Virtualization

• A new licensing policy allows up to 4 virtual instances per physical instance of Windows Server 2003 R2 Enterprise and unlimited virtual instances per physical instance of Windows Server 2003 R2 Datacenter

Utilities and SDK for UNIX-Based Applications

This add-on gives a relatively full Unix development environment. It consists of:

• Base Utilities
• SVR-5 Utilities
• Base SDK
• GNU SDK
• GNU Utilities
• Perl 5
• Visual Studio Debugger Add-ins

Support lifecycle[edit]

On July 13, 2010, Windows Server 2003 and its family of operating systems were moved from Mainstream Support to the Extended Support phase as it marks the progression of the legacy operating system through the Microsoft Support Lifecycle Policy. During the Extended Support Phase, Microsoft will continue to provide security updates every month for Windows Server 2003; however, free technical support, warranty claims, and design changes are no longer being offered.

On July 14, 2015, all Windows Server 2003 support, including security updates and security-related hotfixes, will be terminated.

Windows XP x64 and Server 2003 x64 Editions

On 25 April 2005, Microsoft released Windows XP Professional x64 Edition and Windows Server 2003, x64 Editions in Standard, Enterprise and Datacenter SKUs. Windows XP Professional x64 Edition is an edition of Windows XP for x86-64personal computers. It is designed to use the expanded 64-bit memory address space provided by the x86-64 architecture.

Windows XP Professional x64 Edition is based on the Windows Server 2003 codebase; with the server features removed and client features added. Both Windows Server 2003 x64 and Windows XP Professional x64 Edition use identical kernels.

Windows XP Professional x64 Edition is not to be confused with Windows XP 64-bit Edition, as the latter was designed forIntel Itanium processors. During the initial development phases, Windows XP Professional x64 Edition was namedWindows XP 64-Bit Edition for 64-Bit Extended Systems.

Windows Server 2003 R2

Windows Server 2003 R2, an update of Windows Server 2003, was released to manufacturing on 6 December 2005. It is distributed on two CDs, with one CD being the Windows Server 2003 SP1 CD. The other CD adds many optionally installable features for Windows Server 2003. The R2 update was released for all x86 and x64 versions. Windows Server 2003 R2 Enterprise Edition was not released for Itanium.

Windows Fundamentals for Legacy PCs

In July 2006, Microsoft released a thin-client version of Windows XP Service Pack 2, called Windows Fundamentals for Legacy PCs (WinFLP). It is only available to Software Assurance customers. The aim of WinFLP is to give companies a viable upgrade option for older PCs that are running Windows 95, 98, and Me that will be supported with patches and updates for the next several years. Most user applications will typically be run on a remote machine using Terminal Services or Citrix.

Windows Home Server

Windows Home Server (codenamed Q, Quattro) is a server product based on Windows Server 2003, designed for consumer use. The system was announced on 7 January 2007 by Bill Gates. Windows Home Server can be configured and monitored using a console program that can be installed on a client PC. Such features as Media Sharing, local and remote drive backup and file duplication are all listed as features.

2006–2008: Windows Vista—Smart on security

Windows Vista is released in 2006 with the strongest security system yet. User Account Control helps prevent potentially harmful software from making changes to your computer. In Windows Vista Ultimate, BitLocker Drive Encryption provides better data protection for your computer, as laptop sales and security needs increase. Windows Vista also features enhancements to Windows Media Player as more and more people come to see their PCs as central locations for digital media. Here you can watch television, view and send photographs, and edit videos.

Design plays a big role in Windows Vista, and features such as the taskbar and the borders around windows get a brand new look. Search gets new emphasis and helps people find files on their PCs faster. Windows Vista introduces new editions that each have a different mix of features. It's available in 35 languages. The redesigned Start button makes its first appearance in Windows Vista.

Geek trivia: More than 1.5 million devices are compatible with Windows Vista at launch.

Windows Vista Ultimate

The Windows Vista desktop

Windows Vista

Windows Vista was released on 8 November 2006 to business customers, consumer versions following on 30 January 2007. Windows Vista intended to have enhanced security by introducing a new restricted user mode called User Account Control, replacing the "administrator-by-default" philosophy of Windows XP. One major difference between Vista and earlier versions of Windows, Windows 95 and later, is that the original start button was replaced with just the Windows icon. Vista also features new graphics features, the Windows Aero GUI, new applications (such asWindows Calendar, Windows DVD Maker and some new games including Chess, Mahjong, and Purble Place), Internet Explorer 7, Windows Media Player 11, and a large number of underlying architectural changes. Windows Vista has the version number NT 6.0.

Windows Vista ships in six editions:

• Starter (only available in developing countries)
• Home Basic
• Home Premium
• Business
• Enterprise (only available to large business and enterprise)
• Ultimate (combines both Home Premium and Enterprise)

All editions (except Starter edition) are currently available in both 32-bit and 64-bit versions. The biggest advantage of the 64-bit version is breaking the 4 gigabyte memory barrier, which 32-bit computers cannot fully access.

Windows Server 2008

Windows Server 2008, released on 27 February 2008, was originally known as Windows Server Codename "Longhorn". Windows Server 2008 builds on the technological and security advances first introduced with Windows Vista, and is significantly more modular than its predecessor, Windows Server 2003.

Windows Server 2008 ships in ten editions:

• Windows Server 2008 Standard Edition (32-bit and 64-bit)
• Windows Server 2008 Enterprise Edition (32-bit and 64-bit)
• Windows Server 2008 Datacenter Edition (32-bit and 64-bit)
• Windows HPC Server 2008
• Windows Web Server 2008 (32-bit and 64-bit)
• Windows Storage Server 2008 (32-bit and 64-bit)
• Windows Small Business Server 2008 (64-bit only)
• Windows Essential Business Server 2008 (32-bit and 64-bit)
• Windows Server 2008 for Itanium-based Systems
• Windows Server 2008 Foundation Server

2009: Windows 7 introduces Windows Touch

The Windows 7 desktop

Windows 7 OS

Windows 7 is released for the wireless world of the late 2000s. Laptops are outselling desktops, and it's become common to connect to public wireless hotspots in coffee shops and private networks in the home.

Windows 7 includes new ways to work with windows—like Snap, Peek, and Shake—that improves functionality and makes the interface more fun to use. It also marks the debut of Windows Touch, which lets touchscreen users browse the web, flip through photos, and open files and folders.

Geek trivia: Windows 7 is evaluated by 8 million beta testers worldwide before it's released.

Windows 7 and Windows Server 2008 R2

Windows 7 was released to manufacturing on 22 July 2009, and reached general retail availability on 22 October 2009.^[20][21] It was previously known by the codenames Blackcomb and Vienna. Windows 7 has the version number NT 6.1.

Some features of Windows 7 are faster booting, Device Stage, Windows PowerShell, less obtrusive User Account Control, multi-touch, and improved window management.^[22] Features included with Windows Vista and not in Windows 7 include the sidebar (although gadgets remain) and several programs that were removed in favor of downloading their Windows Live counterparts.

Windows 7 ships in six editions:^[23]

• Starter (available worldwide)
• Home Basic
• Home Premium
• Professional
• Enterprise (available to volume-license business customers only)
• Ultimate (available to retail market with limited availability to OEMs)

In some countries (Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, United Kingdom, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, and Switzerland), there are other editions that lack some features such as Windows Media Player, Windows Media Center and Internet Explorer called names such as "Windows 7 N." Microsoft focuses on selling Windows 7 Home Premium and Professional. All editions, except the Starter edition, are available in both 32-bit and 64-bit versions. Unlike the corresponding Vista editions, the Professional and Enterprise editions are supersets of the Home Premium edition.

At the Professional Developers Conference (PDC) 2008, Microsoft also announced Windows Server 2008 R2, as the server variant of Windows 7. Windows Server 2008 R2 ships in 64-bit versions (x64 and Itanium) only.

Windows Home Server 2011

Windows Home Server 2011 code named 'Vail' was released on 6 April 2011. Windows Home Server 2011 is built on the Windows Server 2008 R2 code base.^[26] It follows the release of Windows Home Server Power Pack 3 which added support for Windows 7 to Windows Home Server. Windows Home Server 2011 is considered a "major release". (Its predecessor having been built on Windows Server 2003) and only supports x86-64 hardware.

Windows Thin PC

In 2011, Microsoft introduced Windows Thin PC or WinTPC, which is a feature- and size-reduced locked-down version of Windows 7 expressly designed to turn older PCs into thin clients. WinTPC is available for software assurance customers and relies on cloud computing in a business network. Wireless operation is supported since WinTPC has full wireless stack integration, but wireless operation may not be as good as the operation on a wired connection.

2012: Windows 8 features apps and tiles

A PC running Windows 8

Windows 8 Pro

Windows 8 is a reimagined operating system, from the chipset to the user experience, and introduces a totally new interface that works smoothly for both touch and mouse and keyboard. It functions as both a tablet for entertainment and a full-featured PC for getting things done. Windows 8 also includes enhancements of the familiar Windows desktop, with a new taskbar and streamlined file management.

Windows 8 features a Start screen with tiles that connect to people, files, apps, and websites. Apps are front and center, with access to a new place to get apps—the Windows Store—built right in to the Start screen.

Along with Windows 8, Microsoft also launches Windows RT, which runs on some tablets and PCs. Windows RT is designed for sleek devices and long battery life, and exclusively runs apps from the Windows Store. It also comes with a built-in version of Office that's optimized for touchscreens.

Geek trivia: Power users notices that Windows 8 makes the detection and correction of file system errors both more transparent and less intrusive.

Windows 8 and Windows Server 2012

Windows 8 is the current version of Microsoft Windows. One edition, Windows RT, runs on some system-on-a-chip devices with mobile 32-bit ARM (ARMv7) processors. Windows 8 features a redesigned user interface, designed to make it easier for touchscreen users to use Windows. The interface introduced an updated Start menu known as the Start screen, and a new full-screen application platform. The desktop interface is also present for running windowed applications, although Windows RT will not run any desktop applications not included in the system. On the Building Windows 8 blog, it was announced that a computer running Windows 8 can boot up much faster than Windows 7. New features also include USB 3.0 support, the Windows Store, the ability to run from USB drives with Windows To Go, and others.

Windows 8 is available in the following editions:

• Windows 8
• Windows 8 Pro
• Windows 8 Enterprise
• Windows RT

The first public preview of Windows Server 2012 was also shown by Microsoft at the 2011 Microsoft Worldwide Partner Conference.

Windows 8 Release Preview and Windows Server 2012 Release Candidate were both released on 31 May 2012. Product development on Windows 8 was completed on 1 August 2012, and it was released to manufacturing the same day.Windows Server 2012 went on sale to the public on 4 September 2012. Windows 8 went on sale 26 October 2012.

Windows 8.1 and Windows Server 2012 R2 were released on 17 October 2013. Windows 8.1 is available as an update in theWindows store only for Windows 8 users and also available to download for clean installation. The update adds new options for resizing the live tiles on the Start screen.

2013: Windows 8.1 expands the Windows 8 vision

source for this are the ff links below:
http://windows.microsoft.com/en-PH/windows/history#T1=era0

http://en.wikipedia.org/wiki/History_of_Microsoft_Windows