ive had this problem, generaly i thought it was the ram, as it was before, i got some replacment ram and started getting this error when i was exciting games.

All uou have to do, very simple, is first uninstall your graphics card, update your motherboard, download the latest GFX drivers and install them straight away so it updates from freshly installing your graphics card to the latest.

Also it wouldnt do any harm to update windows as much as possible, this means SP2, ignore the bad news youve heard about it.

Also i need you lot to do one thing.

Goto Start > RUN > type Chkdsk C:
let it run throught that program and if you get a Blue screen once its done, its your windows installiation, otherwise its just your gfx. So hope it all works out