MaverickUK

It's a video problem, indefinately. The best thing to do is run memtest96 on your RAM modules (one at a time) for at least three hours and see if it reports any errors, if it does, this would point towards a memory issue. Unplug and reseat your video card to it's current position - also as you have reinstalled your system a few times, this should rule out driver conflictions, although you should make sure this is not a driver issue by running your PC in safe mode - choose option "Safe mode with networking". The resaon i suggest the video drivers is because at a guess, i think you have reinstalled all motherboard drivers as soon as the reinstall of XP was complete, thus not giving your PC time to show up the syptoms without the drivers.

If this does help, i do not want money as a reward, although you could always donate to the TechSupportForum as a gesture of good-will. Let us know how this goes.

Regards,
Nick.

edit: I remember having this problem in the past, although i really do not remember what the issue was - i know it was one of two things; i replaced the video card or i replaced the driver (really cannot remember which).