My computer shuts down unexpectedly...no warnings no error messages. I just installed Windows 7 successfully and it shut down after a few minutes online. Sometimes it shuts down after 2 or 3 minutes, sometimes longer. I was hoping it was a virus, so I did a clean install with Windows 7. Looks like that didn't help. Could it be the hard drive? Is there any way to troubleshoot what the problem could be? Could something inside the computer be loose? Any help would be really appreciated!