The addition of a five-year "extended support" phase to Windows XP will take effect in May 2009. In Microsoft parlance, extended support is the period when all support is fee-based and non-security hotfixes are produced only for corporate customers. Until April of 2009, Windows XP Home and Media Center will remain in what is called "mainstream support," which offers some no-charge support and free updates that don't deal with security issues.
Previously, all support for Windows XP Home was slated to end two years after the release of Vista, in other words, at the end of January 2009.
Windows XP debuted in October 2001. By the time it exits extended support, it will have been viable for more than 12 years, a record for Microsoft. In comparison, Windows Vista, which will ship to retail next week, is slated to enjoy support for just 10 years, until April 2017.
Microsoft gave no reason for the support changes to Windows XP.