Windows 2000

Windows 2000 is an operating system for use on both client and server computers. It was produced by Microsoft and released to manufacturing on December 15, 1999, and launched to retail on February 17, 2000. It is the successor to Windows NT 4.0, and is the last version of Microsoft Windows to display the "Windows NT" designation. It is succeeded by Windows XP (released in October 2001) and Windows Server 2003 (released in April 2003). During development, Windows 2000 was known as Windows NT 5.0.

Four editions of Windows 2000 were released: Professional, Server, Advanced Server, and Datacenter Server; the latter was both released to manufacturing and launched months after the other editions. While each edition of Windows 2000 was targeted at a different market, they shared a core set of features, including many system utilities such as the Microsoft Management Console and standard system administration applications.

Windows 2000 introduces NTFS 3.0, Encrypting File System, as well as basic and dynamic disk storage. Support for people with disabilities was improved over Windows NT 4.0 with a number of new assistive technologies, and Microsoft increased support for different languages and locale information. The Windows 2000 Server family has additional features including the ability to provide Active Directory services.

Windows 2000 can be installed through either a manual or unattended installation. Unattended installations rely on the use of answer files to fill in installation information, and can be performed through a bootable CD using Microsoft Systems Management Server, by the System Preparation Tool.

Microsoft marketed Windows 2000 as the most secure Windows version ever at the time; however, it became the target of a number of high-profile virus attacks such as Code Red and Nimda. For ten years after its release, it continued to receive patches for security vulnerabilities nearly every month until reaching the end of its lifecycle on July 13, 2010.

History
Windows 2000 is a continuation of the Microsoft Windows NT family of operating systems, replacing Windows NT 4.0. The original name for the operating system was Windows NT 5.0 and its Beta 1 was released in September 1997, followed by Beta 2 in August 1998. On October 27, 1998, Microsoft announced that the name of the final version of the operating system would be Windows 2000, a name which referred to its projected release date. Windows 2000 Beta 3 was released in January 1999. NT 5.0 Beta 1 was similar to NT 4.0, including a very similar themed logo. NT 5.0 Beta 2 introduced a new 'mini' boot screen, and removed the 'dark space' theme in the logo. The NT 5.0 betas had very long startup and shutdown sounds, though these were changed in the early Windows 2000 beta, but during Beta 3, a new piano-made startup and shutdown sounds were made, featured in the final version as well as in Windows ME. The new login prompt from the final version made its first appearance in Beta 3 build 1946 (the first build of Beta 3). The new, updated icons (for My Computer, Recycle Bin etc.) first appeared in Beta 3 build 1976. The Windows 2000 boot screen in the final version first appeared in Beta 3 build 1994. Windows 2000 did not have a codename because, according to Dave Thompson of Windows NT team, "Jim Allchin didn't like codenames".

Windows 2000 Service Pack 1 was codenamed "Asteroid" and Windows 2000 64-bit was codenamed "Janus." During development, there was a build for the Alpha which was abandoned some time after RC1 after Compaq announced they had dropped support for Windows NT on Alpha. From here, Microsoft issued three release candidates between July and November 1999, and finally released the operating system to partners on December 12, 1999. The public could buy the full version of Windows 2000 on February 17, 2000. Three days before this event, which Microsoft advertised as "a standard in reliability," a leaked memo from Microsoft reported on by Mary Jo Foley revealed that Windows 2000 had "over 63,000 potential known defects." After Foley's article was published, she claimed that Microsoft blacklisted her for a considerable time. However, Abraham Silberschatz et al. claim in their computer science textbook that "Windows 2000 was the most reliable, stable operating system Microsoft had ever shipped to that point. Much of this reliability came from maturity in the source code, extensive stress testing of the system, and automatic detection of many serious errors in drivers." InformationWeek summarized the release "our tests show the successor to NT 4.0 is everything we hoped it would be. Of course, it isn't perfect either." Wired News later described the results of the February launch as "lackluster." Novell criticized Microsoft's Active Directory, the new directory service architecture, as less scalable or reliable than its own Novell Directory Services (NDS) alternative.

Windows 2000 was first planned to replace both Windows 98 and Windows NT 4.0. However, this changed later. Instead, an updated version of Windows 98 called Windows 98 Second Edition was released in 1999; this was followed by Windows ME (the last DOS-based Windows ever released) in the summer of 2000.

On or shortly before February 12, 2004, "portions of the Microsoft Windows 2000 and Windows NT 4.0 source code were illegally made available on the Internet." The source of the leak remains unannounced. Microsoft issued the following statement:

"'Microsoft source code is both copyrighted and protected as a trade secret. As such, it is illegal to post it, make it available to others, download it or use it.'"

Despite the warnings, the archive containing the leaked code spread widely on the file-sharing networks. On February 16, 2004, an exploit "allegedly discovered by an individual studying the leaked source code" for certain versions of Microsoft Internet Explorer was reported.

Microsoft planned to release a 64-bit version of Windows 2000, which would run on 64-bit Intel Itanium microprocessors, in 2000. However, the first officially-released 64-bit editions of Windows were Windows Datacenter Server Limited Edition and later Windows Advanced Server Limited Edition, which were based on the pre-release Windows Server 2003 (then known as Windows .NET Server) codebase. These editions were released in 2002, were shortly available through the OEM channel and then were superseded by the final versions of Windows Server 2003.

Windows 2000 have received four full service packs and one rollup package following SP4, which is the last service pack. These include SP1 on August 15, 2000, SP2 on May 16, 2001, SP3 on August 29, 2002 and SP4 on June 26, 2003. Microsoft had originally intended to release the Windows 2000 SP5 but was cancelled early in the development, and instead released Update Rollup 1 for SP4, a collection of all the security hotfixes and other related issues. The Update Rollup does not include all non-security related hotfixes and is not subjected to the same extensive regression testing as a full service pack. Microsoft states that this update will meet customers' needs better than a whole new service pack, and will still help Windows 2000 customers secure their PCs, reduce support costs, and support existing computer hardware.

Windows 2000 was superseded and embraced by the newer operating systems, Windows XP and Windows Server 2003. The Windows 2000 family of operating systems have moved from mainstream to extended support on June 30, 2005. Microsoft says that this marks the progression of Windows 2000 through the Windows lifecycle policy. Under mainstream support, Microsoft freely provides design changes if any, service packs and non-security related updates in addition to security updates, whereas in extended support, service packs are not provided and non-security updates require contacting the support personnel by e-mail or phone. Under the extended support phase, Microsoft continued to provide critical security updates every month for all components of Windows 2000 (including Internet Explorer 5.0 SP4) and paid per-incident support for technical issues. Because of Windows 2000's age, many of the updated versions of components such as Windows Media Player 11 and Internet Explorer 7, are not available in the operating system. In the case of Internet Explorer, Microsoft said in 2005 that, "some of the security work in IE 7 relies on operating system functionality in XP SP2 that is non-trivial to port back to Windows 2000.

Windows 2000 can be upgraded to any version after Windows XP/Server 2003, which is Windows Vista, 7, 8, 8.1 and 10, together with Windows Server 2008 and 2012. A fresh install is required at the point of time.