BSOD

I borrowed a friend's video card for about a week. I still got blue screens and random crashes, although it wasn't DX that was crashing. Today I tested all the lines on my PSU with a multimeter--everything was within a tolerable range. I am beginning to suspect the motherboard, but I hate to replace it without a more definite confirmation. Right now I am running scandisk on my two disks. I doubt this has anything to do with it, but I wanted to check everything I could. Any more ideas?

I pulled one stick of RAM. I played a video game for several hours without a BSOD. I then ran the Prime 95 tests for several hours on each without a single error. I was looking around at RAM prices when I noticed that my RAM configuration is known to cause problems without the F12 Bios update for the motherboard. I checked, and sure enough I wasn't up to date. I have just flashed the BIOS to F12. I am going to put the stick of RAM back in and do some testing to see if this was the issue.

I have been effectively trying to fix this computer for a year. It feels nice to be getting some useful data for once. This F12 Bios was not in existence when I put this machine together, however. I'll report back after testing.