BleepingComputer.com: Possible Video Card Problem with Win 7

I overhauled my PC by replacing MOBO, CPU (Intel I5) and HDD and reused my case, PS and video card (Nvidia GeForce 7900 GT/GTO)

The computer csreen goes Black, Blue or crazy patterns if I try to view a JPG file, change resolution, or let it go to standby with no useage. Cannot clear the screen to operate. Computer does not crash, just the video goes crazy.

Any ideas what is going on?

FWIW driver is up to date according to Win 7.