Windows xp but its not mine

Hi there i have searched all over the net for this problem, I have never experienced this before. I had the other day shut my pc down which by the way is Running Windows XP Pro 32 bit. Later upon starting it up i found my desk top had Disappeared and everything had been reset back to default almost as though i had just loaded a fresh copy of windows.. All my files had been placed in a folder on the hard drive.. Id did think this was crazy, but thought it had something to do with the system restore i had done earlier.. I carried on using this and never bothered to set up everything as my files were safe in a folder..
However today after restarting i have found now my correct desktop has returned with all my files, but the desk top that was on there with some more new files has gone and i cannot find it anywhere.. I have made a point of changing all my passwords.. I have never encountered this ever? is there anyway to retrieve those files of that recent installed version?

Hello yawroc,

Suggest you start a topic at What The Tech in this forum: Microsoft Windows™

The techs who volunteer there may be able to help.

Best regards. :)