Months ago, Microsoft began warning XP SP1/SP1a users that support would end Oct. 10, and urged them to update to Windows XP SP2. As a parting gift, however, Microsoft released 10 patches for XP SP1/SP1a that included 2 pegged critical, 3 as "important," 2 "moderate," and 3 as "low."
Under Microsoft's current lifecycle policy, it promises to support Service Packs with security updates for 12-24 months after the release of a succeeding SP. Windows XP as a whole will age out of support only after two years have passed from the time Windows Vista is officially released.
Windows XP SP2, the free-of-charge update first issued in 2004, can be downloaded from the Microsoft Web site.