Computer freezing then graphics card stops working

hello, i am having some trouble with my computer. it started when i was playing a game and my game went crazy with these weird blue lines and froze... so i hit the restart on my computer and when it was back up the resolution was 800x600.

so i saw that i had some windows updates i hadnt installed and i saw something for nvidia so i installed all the patches and i think there was a service pack too... but the nvidia one failed to install for some reason.

Then i restarted and my computer was still in that crappy resolution so i look around and find that my graphics card has this message in the device manager "Windows has stopped this device because it has reported problems. (Code 43)"

so i then uninstall the drivers restart and reinstall updated drivers for the video card... the resolution is fine now and everything seems to be working fine, but about an hour in, the computer freezes and i have to restart. and i get the same error again that says windows stopped the device.

so i reinstall drivers again but use some older ones, but that still isnt working and the same freezing problem device stoppage thing keeps happening.

so can this problem be fixed with a new graphics card or is there something wrong with the windows service pack i installed and i need that nvidia update that failed to install for some reason and i am unable to get it again from windows update.

here some computer specs:

windows 7 ultimate 32-bit 6.1
nvidia geforce 8800 gtx graphics card