I'm running Windows XP Professional on a PC which is less than a year old. About 3 months ago I got an error on boot saying windows could not find my profile. At this point it created a temp one. On this occasion I copied the temp data back into my existing profile and carried on using it. After another month it died again and, once again set me up a temp user. Each time this happens I lose everything related to my profile (desktop, start menu, etc). I ran checks on the hard disk and these suggested nothing was wrong so this seems a software issue not a disk problem.
On the advice of my computer manufacturer I am now considering reinstalling Windows but just wanted to check if there's any other ideas for things I might be able to try. Any suggestions for what could be causing the problem would also be gladly appreciated.