Sudden graphic anomolies?

Sometimes I will notice theirs some weird graphic glitches such as black boxes or real strange things appearing at certain areas in town. Never used to happen until today I noticed my display drivers kept crashing and repairing while in gws.

I updated it but notice all these weird graphic glitches in gws.

I use 8800gtx quad core, 680i mobo. Vista home premium.

I also noticed it started when I tried to upgrade drivers and the drivers would like crash my comp to a black screen and didn't seem to finish until I upgraded in safe mode.