I have a fan underneath and the card havent overheated in ages. It happened a lot when i played oblivion and fallout 3 at the same time earlier, but i easily fixed it that time :P No, it happens sometimes at once when i start the game, and sometimes it wont happen in a week. Normally when it has happened once it will happen many more times that same day.

ah, btw, it happened more often after i changed from windows vista to windows 7, might it be that my computer aint compatible with 64 bit? should i format to 32 bit instead? (got all windows versions legally from 2000 to windows 7, profesional version)

(can the computer shut down because of dust without overheating? and if so, whats best way of getting rid of dust? ive tried pretty many things, and blowing out dust seems to have been the one working the best so far)