You're off topic for this forum, which is dedicated to Windows Live OneCare. You may want to try the Microsoft Public newsgroups here: http://www.microsoft.com/communities/newsgroups/list/en-us/default.aspx
It sounds to me like your reinstall of XP Home was not successful. You may also want to pursue this with the PC manufacturer's support pages.
-steve
Microsoft MVP Windows Live / Windows Live OneCare & Live Mesh Forum Moderator