I've got an Nvidia 540 GT (a newer Nvidia generation) and 'Had' this problem. I fixed it by using the nvidia 'optimums' app which allows me to switch to use my Intels i-7's built in GPU instead.
And you are still 18xx? ops:h and that was like 400 games ago.
It used to happen on ATI as well. It's an OS issue more so than GPU related, although GPU drivers could play a role too I assume.I think so. Old graphic cards were optimized for Win XP, but not for win 7. All posts i've read about this issue, were from guys that had nvidia GPU.
upgraded to SP1 and followed instructions to render in 32-bit color (on voobly). Not sure which one fixed it but I've played 20+ games with no crashes. Hopefully gone for good.
Thanks again.
Go back to XP windows 7 sucks anyway