Windows 2000

Windows 2000

Version of Microsoft Windows
OS family	Windows NT
Version	5.0
Preliminary name	Windows NT 5.0
Architecture	x86
Latest build	5.0.2195.7045 (Update Rollup 1)
Release date	2000-02-17
Support end	2010-07-13
Replaces
Windows NT 4.0
Replaced by
Windows XP Windows Server 2003

Windows 2000 (known as Windows NT 5.0 during development) is an NT-based version of Windows released by Microsoft that succeeded Windows NT 4.0. It reached general availability on 17 February 2000 after releasing to manufacturing two months prior on 15 December 1999. Windows 2000 was initially intended to be a counterpart to Windows 98 (much as NT 4.0 was to Windows 95), but after delays, it was intended to replace both Windows 98 (from which it integrated many multimedia-focused features, including full, proper DirectX support) and NT 4.0, but after further delays and slippage, it was aimed more squarely at the corporate market.

Even though Windows 2000 is intended mainly for use in businesses and the consumer market was targeted by Windows Me, many home users installed Windows 2000 Professional at the time due to the highly significant issues that plagued Windows Me. Windows 2000 was ultimately replaced by Windows XP and Windows Server 2003.

During the course of its support, four Service Packs and an update rollup were released for Windows 2000. Microsoft had originally intended to release a fifth service pack for Windows 2000, but eventually canceled it, and instead released the Update Rollup 1 for Windows 2000 Service Pack 4 in 2005, which is a collection of all the security-related hotfixes and some other significant issues. The Update Rollup does not include all non-security related hotfixes and is not subjected to the same extensive regression testing as a proper service pack.

Mainstream support for Windows 2000 ended on 30 June 2005 and extended support ended on 13 July 2010, over ten years after its release.

Name

Slide from an internal Microsoft presentation discussing the naming of Windows 2000

Prior to the final announcement, Windows 2000 was called Windows NT 5.0 in both marketing materials and the operating system builds themselves. On 27 October 1998, Microsoft announced the renaming of the Windows NT 5.0 product line to Windows 2000, which according to Microsoft reflects the growing mainstream role of Windows NT. The name continues the year-based naming scheme for consumer-oriented versions of Windows, which started with Windows 95. This reflected the initial plan for Windows 2000 to succeed both the consumer-oriented Windows 98 and business-oriented Windows NT 4.0 operating systems. However, in the end, Windows Millennium Edition was released to succeed Windows 98, which led to confusion between the two. Due to the removal of the NT moniker, Windows 2000 branding often included the "Built on NT Technology" tagline to clear out doubts.

An internal Microsoft presentation released during the U.S. v. Microsoft trial titled "Windows Launch Review" from 21 November 1997 briefly discusses naming options of the workstation edition. According to the document, Microsoft considered the following names:

• Windows NT Workstation 5.0
• Windows NT Client 5.0
• Windows NT Desktop 5.0
• Windows NT 5.0
• Windows 99/2000

Editions

There are 4 major editions of Windows 2000:

• Windows 2000 Professional is the client version, which succeeds Windows NT Workstation. It supports up to 2 CPUs and a maximum of 4 gigabytes of RAM.
• Windows 2000 Server is the base server version, which supports up to 4 CPUs and a maximum of 4 gigabytes of RAM.
• Windows 2000 Advanced Server is the successor of Windows NT Server, Enterprise Edition. It supports up to 8 CPUs and a maximum of 8 gigabytes of RAM.
• Windows 2000 Datacenter Server is a newly introduced edition, which was only available via OEMs. It supports up to 32 CPUs and 32 gigabytes of RAM.

Microsoft has also released Small Business Server 2000 and BackOffice Server 2000, which are based on Windows 2000 Server and also include other Microsoft server software, such as Exchange Server and SQL Server.

Windows Powered

Certain network-attached storage (NAS) devices are known to have shipped with a version of Windows 2000 Advanced Server branded as "Windows Powered". This edition was likely only available to select OEMs as a baseline system that would be further customized for a specific workload by installing the Server Appliance Kit. The kit can also be applied onto a stock Server or Advanced Server copy, which led to false claims that installing it would convert the stock copy into Windows Powered.

The branding is controlled by the 0x0400 product suite flag, which appears as "Server Appliance" in the registry. This flag was introduced with Service Pack 1, alongside the Personal product suite (0x0200). The mechanism enabling the Powered branding was apparently removed at some point, as there are reports of an update causing the system to revert back to Advanced Server branding. The same product suite flag was later reused for Windows Server 2003 Web Edition, although the registry string changed to "Blade" (the codename for the edition).

Several fake copies of what was claimed to be Windows Powered have been produced, commonly by replacing the branding resources used by a regular server edition.

DEC Alpha version

The DEC Alpha version of Windows 2000 was in development before was canceled in August 1999, when Compaq announced it would terminate future development of Windows NT on the platform. This happened two weeks before the official Release Candidate 2 build was compiled. The cancellation affected both the 32-bit version inherited from prior versions, as well as a new 64-bit port (see § 64-bit version).

Several improvements were made to the DEC Alpha version, such as the inclusion of the FX!32 emulator for running 32-bit x86 applications out of box. Compared to the previous standalone downloads for Windows NT 4.0, FX!32 is now integrated into Wx86, Microsoft's own attempt at supporting 32-bit x86 applications on non-x86 platforms. The Very Large Memory APIs for managing memory in the 64-bit address space was also implemented.

Very Large Memory API

The 32-bit version of Windows 2000 for Alpha was intended to include a new set of functions dealing with memory above the 4 GB boundary, dubbed the Very Large Memory (VLM) functions, including VirtualAllocVlm and MapViewOfFileVlm, that would allocate memory in the address space above 4 GB. This memory could not be used with most Windows API functions, since the application binary interface only guaranteed that the lower 32 bits of the pointer would be properly respected. However, since certain programs such as database software tended to mostly do its own processing of data and not involve API functions, they could store large amounts of data in the VLM space. This approach is similar to WINMEM32, a library for Windows 3.0 and 3.1x that could be used to run 32-bit code with 32-bit pointers, under a similar limitation that no API calls or I/O could be done.

The VLM functions are documented as late as the November 1999 Platform SDK, which documents Windows 2000 RC2, and VLM is implemented on the x86 versions of Windows 2000, but returns an error code. The MSDN library included with Visual Studio .NET 7.0 Beta 1 does not include documentation of VLM, but does include a WinHEC 1999 whitepaper discussing Address Windowing Extensions (AWE), a similar technology which uses bank switching to make memory above 4 GB accessible from the 32-bit address space (which also makes it possible to use regular API functions with AWE-managed memory), and how it is supported on both the x86 and Alpha versions of Windows 2000, but that VLM is not going to be removed since it is already in use.

64-bit version

A 64-bit version targeting the DEC Alpha and Intel Itanium processor architectures was also in development. The broader 64-bit port effort was codenamed Sundown as a jab at Sun Microsystems, since the company's Solaris operating system would be one of the main competitors in the 64-bit operating system market. The port was originally developed on DEC Alpha machines, which were already supported by Windows NT, albeit using a 32-bit application binary interface on the otherwise 64-bit processor. This version was officially canceled when Compaq canceled further Windows NT on Alpha development, although it continued to be maintained internally even during early Windows XP development due to its practicality before prototype Itanium hardware was available.

The Itanium version of Windows 2000, codenamed Janus, was demonstrated at the 1999 Professional Developers Conference and later the NetWorld+Interop show in May 2000. At the latter, it was stated that it had been in development for three years by that point, suggesting development started at some point in 1997. This version had a slated release date of sometime before the end of 2000, intended to coincide with Intel's launching of the Itanium architecture. However, as Intel faced delays during development, this version also got ultimately canceled and the Itanium port first shipped with Windows XP 64-Bit Edition.

It is rumored that IA-64 builds of Windows 2000 were sent out to OEMs which worked on Itanium-based machines, such as Fujitsu-Siemens and Hewlett-Packard (which is supported by references to this in images in early HP i2000 manuals), but not much is known about these alleged builds, nor has anything leaked in relation to these alleged builds.

Source code leak

In early 2004, a portion of the Windows 2000 source code leaked online, together with the source code of Windows NT 4.0. The source of the leak was traced to Mainsoft, the developer of MainWin, an application that allowed developers to port existing Windows programs to Unix systems, whose development required access to selected portions of Windows source code under Windows Interface Source Environment program. In response, Microsoft released the following statement:

On Thursday, February 12, Microsoft became aware that portions of the Microsoft Windows 2000 and Windows NT 4.0 source code were illegally made available on the Internet. Subsequent investigation has shown this was not the result of any breach of Microsoft's corporate network or internal security, nor is it related to Microsoft's Shared Source Initiative or its Government Security Program, which enable our customers and partners, as well as governments, to legally access Microsoft source code. Microsoft reaffirms its support for both the Shared Source Initiative and the Government Security Program.

Microsoft continues to work closely with the U.S. Federal Bureau of Investigation and other law enforcement authorities on this matter. 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. Microsoft will take all appropriate legal actions to protect its intellectual property. These actions include communicating both directly and indirectly with those who possess or seek to possess, post, download or share the illegally disclosed source code.

Specifically, Microsoft is sending letters explaining to individuals who have already downloaded the source code that such actions are in violation of the law. Additionally, Microsoft has instituted the use of alerts on several peer-to-peer clients where such illegal sharing of the source code has taken place. These alerts are designed to inform any user who conducts specific searches on these networks to locate and download the source code that such activity is illegal.

Questions about the ongoing investigation should be referred to the FBI.

— Microsoft Corporation

Despite the warnings, the archive containing the leaked code spread widely on the file-sharing networks and, even later, on open-source repository websites. On 16 February 2004, an exploit allegedly discovered by an individual studying the leaked source code for certain versions of Microsoft Internet Explorer was reported. On 15 April 2015, a repository containing the leaked NT 4.0 source code was removed from GitHub at Microsoft's request, although other repositories hosting the Windows 2000 source code continued to exist in the same website; most of them were taken down by Microsoft's request on 9 April 2021.

Distributed Services Technology Preview

The Distributed Services Technology Preview is a backport of certain components including Active Directory, Microsoft Management Console, Task Scheduler and Windows Script Host from an early build of Windows 2000 to Windows NT 4.0, which was released at the November 1996 PDC. It is notable for being the only available build of these components compiled for the PowerPC architecture; a MIPS version was also planned to be released, but was canceled as Microsoft had dropped support for the architecture weeks prior to the event. The installer for these components continued to be compiled until as late as build 1631.

4.01.45.1

4.01.57.1

System requirements

Microsoft recommends that Windows 2000 should be installed on a system with at least a Pentium 133 MHz processor, 64 MB of RAM (128 MB for Server), 650 MB of hard drive space (1 GB for Server), and a VGA or better display. Windows NT 3.51 or Windows 95 is now needed to upgrade to Windows 2000.

Despite Microsoft's recommendation, it is possible to install Windows 2000 on a 486 processor with as low as 32 MB of RAM.

List of known builds

Beta 1

5.0.1386.1

5.0.1393.1

5.0.1426.1

5.0.1515.1

5.0.1528.1

5.0.1574.1

5.0.1575.1

5.0.1580.1

5.0.1585.1

5.0.1592.1

5.0.1597.1

5.0.1627.1

5.0.1631.1

5.0.1636.1

5.0.1645.1

5.0.1650.1

5.0.1661.1

5.0.1671.1

Interim Developer's Release

5.0.1691.1

5.0.1700.1

5.0.1701.1

5.0.1717.1

5.0.1723.1

5.0.1729.1

5.0.1738.1

5.0.1743.1

5.0.1745.1

5.0.1750.1

5.0.1762.1

5.0.1773.1

Beta 2

5.0.1781.1

5.0.1794.1

5.0.1796.1

5.0.1802.1

5.0.1804.1

5.0.1805.1

5.0.1814.1

5.0.1816.1

5.0.1828.1

5.0.1835.1

5.0.1840.1

5.0.1841.1

5.0.1848.1

5.0.1855.1

5.0.1859.1

5.0.1862.1

5.0.1868.1

5.0.1876.0

5.0.1877.1

Beta 3

5.0.1888.1

5.0.1890.1

5.0.1902.1

5.0.1906.1

5.0.1911.1

5.0.1916.1

5.0.1920.1

5.0.1922.1

5.0.1924.1

5.0.1930.1

5.0.1932.1

5.0.1945.1

5.0.1946.1

5.0.1947.1

5.0.1948.1

5.0.1950.1

5.0.1952.1

5.0.1954.1

5.0.1964.1

5.0.1965.1

5.0.1969.1

5.0.1974.1

5.0.1976.1

5.0.1978.1

5.0.1983.1

5.0.1987.1

5.0.1989.1

5.0.1991.1

5.0.1993.1

5.0.1994.1

5.0.1996.1

5.0.1999.1

5.0.2000.1

5.0.2000.3

5.0.2001.1

5.0.2011.1

5.0.2019.1

5.0.2020.1

5.0.2024.1

5.0.2031.1

Release Candidate 1

5.0.2032.1

5.0.2036.1

5.0.2040.1

5.0.2042.1

5.0.2050.1

5.0.2052.1

5.0.2053.1

5.0.2054.1

5.0.2055.1

5.0.2056.1

5.0.2066.1

5.0.2068.1

5.0.2070.1

5.0.2072.1

Release Candidate 2

5.0.2078.1

5.0.2080.1

5.0.2087.1

5.0.2090.1

5.0.2091.1

5.0.2092.1

5.0.2098.1

5.0.2099.1

5.0.2112.1

5.0.2113.1

5.0.2114.1

5.0.2119.1

5.0.2120.1

5.0.2121.1

5.0.2124.1

5.0.2128.1

Release Candidate 3

5.0.2136.1

5.0.2148.1

5.0.2151.1

5.0.2167.1

5.0.2168.1

5.0.2169.1

5.0.2172.1

5.0.2176.1

5.0.2178.1

5.0.2183.1

Pre-RTM

5.0.2190.1

5.0.2194.1

RTM

5.0.2195.1

Service Pack 1

Beta

5.0.2195.1600

5.0.2195.1610

RTM

5.0.2195.1620

Service Pack 2

Beta

5.0.2195.2793

RTM

5.0.2195.2951

Service Pack 3

Beta

5.0.2195.4448

RTM

5.0.2195.5438

Service Pack 4

Beta

5.0.2195.6623

5.0.2195.6632

5.0.2195.6697

5.0.2195.6704

5.0.2195.6706

5.0.2195.6712

5.0.2195.6715

5.0.2195.6717 (RC 4.79)

5.0.2195.6717 (RC 4.80)

RTM

5.0.2195.6717

Update Rollup 1

Beta

5.0.2195.7020

5.0.2195.7035

RTM

5.0.2195.7045