I have the same video card, one day i turned off my laptop and went to sleep.
The other day when I turned on the laptop (Toshiba Satellite P105-S9337) i noticed it looked a little weird, soon it went black screen and reset itself and there were little squares on the screen aswell. So I boot on safe mode, made a backup and finally switched to Windows 7 Ultimate, though even running a clean formatted HDD install it did not solve the problem.
Ive tried many drivers on laptopvideo2go.com but whenever i found a driver that installed, and I could read Nvidia GeForce Go 7900GS under Graphic Adapter instead of Standard VGA Adapter in Device Manager and reboot to complete install it would also black screen when it got to the Loading Windows screen.
I´m running hopeless here dunno what else to do, thanks for your help