Actrully, it is possible that it may be the HDD. Open up your PC, do you hear weird noises from your HDD? This is what happened to me once or twice. Yes, 4 Virtual drives is a lot, and I'm assuming that you just have the 1 master drive, that would be a lot of stress on the HDD, espeshally if you've been doing this for 2 years. I mean, one of my HDD died after 9 months because it was being heavy used for the entire 9 months.