I have a computer that started freezing after a few minutes from being turned on. The OS is Vista. I have tried reinstalling Vista as well as XP on both the original hard drive and a new hard drive. During installation of both OS's it froze. I would retry and retry and eventually get the install complete but then would freeze when it was started. The CPU fan and power supply seem to be working just fine. Any other ideas I could try? Could the motherboard be bad? Any other suggestions would be great!