I just tried updating the wireless driver and that did not help. But removing the wireless device seemed to help for the once or twice I tried to reboot. I really can't reformat the HD since I have lots of records on it that I don't want to lose. The only other thing I changed was the monitor and I will try the old one again and see if that helps. What robert described is just what it is doing. Does the scan disc frequently and has even shutdown right in the middle of loading a web page.