My computer problems turned out to be both bad memory and the motherboard. Replacing the memory got it to stop rebooting itself and replacing the motherboard got it to stop locking up. After 2 weeks it has not locked up once.

Thanks, but this is the replacemnet RAM I had gotten some generic stuff before and it was pretty much crap. I sent it back and got stuff that was hopefully going to be reliable (and of course, twice as expensive). I honestly don't think that this particular RAM is bad, I think it's the mobo, which is even worse, IMO.

I'm just hoping I can get to a situation that works for me, and not return the mobo.