Here is my situation. My Dad has 1 year old Dell Dimension 8200 running XP Home. A couple of months ago he got the Klez.H virus. I managed to, seemingly, clean the system up and get all things normal. Two days later, the machine will not boot-up. It does the constant reboot cycle and flashes the Blue Screen about Corrupt Registry. I followed the MS Knowledge Base Article Q307545 and restored the system. This allowed me to remove files and all information that my Dad needed to save. Once complete, I Formatted the HDD and started from scratch. Did a clean install of XP. Made sure NAV was updated and all MS software was updated as well. Everything was fine until he turned on his PC two days ago. It booted but came up with Blue Screen and the XP Logo. It looks like the ShutDown screen. At this point, the machine stopped. The cursor was on the screen but that is all. It would not get to the LogOn Screen. SafeMode nor Last Good Configuration would work. I tried everything I could think of, but finally had to do an XP Restore. I booted to the CD and did a Repair (not the Recovery Console). Now the machine is up and all settings and files appear to complete. No Microsoft Software is loaded nor is NAV. In my opinion, there is still something not right. Either the HDD is bad, the RAM is bad or maybe the Power Supply. One thing I did find upon opening the box was the Power Supply connection going to the MotherBoard was not exactly secure. I have no idea if this could cause intermittent problems or not. Obviously, I am going to do another clean install of XP. I have been running XP Home on my PC and refuse to believe it is an OS problem. If you guys were in this situation, would you buy a new HDD or just format the existing one again. Is there anyway there could be a Virus somewhere on the HDD that NAV is not picking up? Any opinions on the Power Supply Plug where it attaches to the Mother Board? Could that be the culprit? Any opinions would be great and thanks for reading.