Last week, I had an issue with Windows 7 booting slow and the network not starting up. I fixed that problem using system restore and cleaning the hard drive and registry. After that, everything was working again, but the network still took longer than usual to start. I was suspecting that something was wrong. Then a few hours ago, my PC unexplainably rebooted itself several times and sometimes got to the point when Windows would not boot up at all. OK, so I was thinking that the PSU went bad. I checked the power connectors and fans; fans worked fine and CoreTemp showed my CPU running at normal operating temperatures. OK, so I reinstalled Windows from my recovery partition. PC restarts kept on going! Windows Experience Index was not detecting my video card. OK, so then I installed the Windows 8 upgrade. After booting up Windows 8, the PC stopped rebooting itself, so it seems that I can rule out any issues with the PSU. Then I ran the WEI again and it gave me a low graphics score. I was thinking bad video card, so I unplugged the power connector and plugged it back in. I rebooted the PC. EVGA Precision X started up this time and I reran the WEI. Scores are back to normal and Windows self-installed the 335.23 WHQL driver. So my video card is OK. Now that it seems that my hardware is fine, but when I started to download Windows updates, the PC froze up. Had to do a hard power reset. Now I'm installing a few updates at a time and will keep doing so until I get the Windows 8.1 Update 1 version. What has caused the issue with my PC? Was it a bad video driver (I was on 337.88 WHQL), viruses (my recent scans detected nothing), loose PSU connection, faulty RAM, or possibly the motherboard / CPU? I certainly would hate to wait four months until the Haswell-E CPUs are released, but if the video card is causing problems, then I have no problem upgrading to a GTX 770. Could it be that my Windows recovery partition was corrupted and I can no longer use Windows 7? What's going on here? I need to get to the root of the issue. I would like to stay on Windows 7, but I can't do that with these issues occurring, even after a clean install. Hell, Windows would not even detect the system disk image stored on a USB hard drive.