My dad's computer started restarting, and giving him the blue screen of death randomly. The problem with his was his memory, every now and then it would crap out and forget something vital to windows, he had to replace it. I forget what exactly the BSOD message was that he got but I would probably recognize it if I saw it.
If it's your memory, and you have more than 1 stick you could try each one of them seperately. Hopefully one of them will still work.