Computer Issues

So for the last week and a half I've re-installed Windows 7, XP, and back to 7 a couple of times to see why I've been getting BSOD. Since the last two runs have had no errors I have to assume that it was either the video card that I still need to test in my other computer or I have a bad HDD which I also still need to test. Either way I hope that this was the last time I have to install an OS for awhile.