Okay, what i'll try later on today is:
Go to Device Manager, uninstall the drivers
, and let Windows 7 detect my card (install VGA-driver
if necessary). Afterwards i'll go to Nvidia's website and install the Graphic Driver, and PhysX. If the problem still appear, I'm sure Nvidia has some older drivers listed. Because the latest driver is from April, and the problem maybe came there, I don't know. But maybe select an older.
Otherwise keep 'em coming with suggestions!