Both the client and server editions of Windows 2000 will exit what Microsoft calls "mainstream" support as of June 30, 2005, and enter its "extended" support period.
Under Microsoft's support policy, a product in the extended portion of its lifespan is still provided with security-related patches, but fixes to issues or problems that the Redmond, Wash.-based developer labels as non-security are available only to firms that have purchased a hot-fix agreement plan.
Windows 2000 users are still waiting for the security-centric "rollup" which was announced in November, 2004, in lieu of an expected fifth service pack. The rollup is scheduled to ship "mid-2005," said Microsoft on its Web site.
The last Microsoft operating system to go through a lifecycle change was Windows NT Server 4.0, which saw its support end the last day of 2004.