Video hardware error -- but independent of video card

Hello,

Last Christmas, I tried to build a PC for my parents. It almost worked, except that every once in a while, the screen would freeze and the display would go all monochromatic, leaving no choice except to push the reset button. This happened with at least half a dozen different video card drivers, although with the older ones, it gave me a straight BSOD whereas with the newer ones it looks like the video was so corrupted that it couldn't even display the blue screen.

The Windows problems and solutions thingy said that this was a video hardware error, so when I came back for this Christmas, I bought a brand new video card (an Nvidia GeForce GT210 which replaced an ATI Radeon HD 4550)... but the only thing that changed was the fact that the screen no longer went monochromatic after a freeze, now it just plain freezes. I've tried updating the BIOS and the chipset drivers and I ran memtest86+ and the Windows Memory Diagnostic, but these did not show any problems.

The zipped html report and output of your jcgriff2 exe are attached. In answer to the questions in the instructions:

1) The OS is Windows 7 Professional x64
2) It is the original OS installed (meaning, there were no others before it)
3) It is a full retail version
4) The hardware is 1 year old except for the new video card which arrived last Tuesday (i.e. 5 days ago)
5) The OS is also 1 year old (it has not been reinstalled)

Thank you for your assistance.

Hi again,

I've been reading some of the other threads on this forum and tried following the instructions. I ran memtest for 6 passes instead of 1 as I did before (still no errors) and I tried uninstalling the Gigabyte power management and other utilities which almost certainly made it worse (the frequency of crashes has increased). I also tried reading the dump files, but all they say on the surface is that the Nvidia (or earlier, before I changed cards, ATI) drivers are at fault and I lack the expertise to understand the details.

Can anybody help? Or is this hopeless and I need a new motherboard?