UNINSTALL SP2

If you cannot get SP2 to load properly or you can’t resolve your problems by any other means then the first thing to uninstall SP2. Normally this is quite straightforward from Add/Remove Programs in Control Panel, it should be listed under Windows XP Updates (make sure the ‘Show Updates’ box is ticked at the top of the page). However, in some cases this may not be displayed and there’s a selection of alternative methods involving the use of a hidden Service Pack uninstaller, System Restore and the XP Recovery Console at:
http://support.microsoft.com/kb/875350