Windows 2000 is a line of operating systems produced by Microsoft for use on personal computers, business desktops, laptops, and servers. Windows 2000 was released to manufacturing on 15th December 1999 and launched to retail on 17 February 2000. It is the successor to Windows NT 4.0, and is the final release of Microsoft Windows to display the "Windows NT" designation. It was succeeded by Windows XP for desktop systems in October 2001 and Windows Server 2003 for servers in April 2003. Windows Me was released seven months after Windows 2000 and one year before Windows XP, but Windows Me was not intended to be, nor did it serve as the successor to Windows 2000. Windows Me was designed for home use, while Windows 2000 was designed for business.
Four editions of Windows 2000 were released, listed here in increasing ranking: Professional, Server, Advanced Server, and Datacenter Server. Additionally, Microsoft sold Windows 2000 Advanced Server Limited Edition and Windows 2000 Datacenter Server Limited Edition, which ran on 64-bit Intel Itanium microprocessors and were released in 2001. 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.
Support for people with disabilities has been improved over Windows NT 4.0 with a number of new assistive technologies, and Microsoft increased support for different languages and locale information.
All versions of the operating system support the Windows NT file system, NTFS 3.0, the Encrypting File System, as well as basic and dynamic disk storage. The Windows 2000 Server family has additional features, including the ability to provide Active Directory services (a hierarchical framework of resources), Distributed File System (a file system that supports sharing of files) and fault-redundant storage volumes. 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 13 July 2010.