So my Windows 7 Professional 64-bit edition just started locking up, and wouldn't even respond to a Ctrl+Alt+Delete. In the end I had to just push the power off button on my PC. However, when I went to turn it back on, it now just reboots when trying to start windows. I didn't add any new hardware or software as far as I'm aware. I have tried running the automatic repair utility, and it says that it is unable to repair the problem. I ran a memory check and that came up clean. Still no dice. =( Am I going to have to reformat the hard drive?