i have this very same problem and i have just updated my drivers to see if it will work. somehow i think its to do with the operating system becuase it says check for any windows updates you might need.
now my problem is solved. i downloaded a nvidia update for my geforce2 gts gfx card and now it is a geforce2 pro. it doesn't close down at the loading screens but my internet connection closes down every 1 and a half hours so i have to keep reconnecting it but that isn't too much of a problem.
Sry to bother you guys again, but i would like to know where to find the max temp allowed by your computer, i tried searching in the BIOS but didnt find it, i have XP home btw.