When this happened to me, it was the hard drive in its death throes. They're only good for about 3-5 years. Luckily, I had most important things backed up on CD's or original software. Since that happened, I now have an external hard drive where I back up EVERYTHING! Once I replaced the hard drive, in the original instance, all was well. But it took the better part of two days to re-install everything. Hopefully, with the external drive, when it happens again, I won't have to spend two days and nights to rectify the situation. Your situation sounds just like mine. Constant re-boots, etc. What a pain.