I had an issue before where I couldn't load any games or videos up without my monitor losing power to it, and my computer rebooting itself. I had found a driver that fixed that issue, but since I have had to wipe my HDD and start anew. I cannot remember the name of that driver. I was curious if anyone had heard any of this problem, and if so maybe suggest a driver? I've tried eVGA's official drivers, and also the Xtreme-G 92.91 driver for the 7800gs and no dice. Any suggestions?

I'm running a very similar configuration here...

Just a little diff... AMD 64X2, 2GB DDR2, evga 7800 gts....

Encountered this problem before and nvidia's standard xp or vista drivers are more than adequate for most anything you want to do.

My money would be on a directx problem not a driver issue.

First Make sure your monitor is connected to the digital video port on the video card not the old standard 15 pin connector. (Card Has Both ports) Depending on your monitor you may need to buy a serial to dvi adapter to be able to connect to the correct port.

Now make sure you current version of direct-x is correct and up to date it should be v.9.0c

If it is out of date goto Microsoft's downloads page and get the most current version.
Install into c:\windows\system32\directx and reboot your pc.

When windows comes back up, prest the start button on the desktop and select the run. Type dxdiag and press enter. Under the "Display tab" there are three options A.DirectDraw Acceleration
B.Direct3D Acceleration
C. AGP Texture Acceleration

Make sure all three are enabled. If they are not then run the tests and enable them. Reboot PC and give it a shot.