BleepingComputer.com: Not all is right with Registry: Computer Freeze

I've had this computer for several years. One time I left a dvd (the Royal Tennanbombs) in the computer one night after falling asleep. The next thing I know, my computer won't work right. The dvd somehow screwed it up...
About 3 years ago I had a friend wipe the computer clean and put the basic stuff back on but now it seem like there are some things not quite right with the registry. The reason I am addressing this problem now is because I didn't use it much after it was "fixed" and my current computer is messed up so now I'm using this one.

The main problems I have now is the screen will freeze up and I can't even move the mouse. I have to turn the power off and then turn it back on for it to work again. Also, I would try to use AVG and everytime, right after the scan would begin, the whole computer would shut off and reboot. Since I couldn't scan for viruses I uninstalled AVG and installed Avira. It ran the scan perfect and found 1 infection: TR/Trash.Gen Trojan. Avira healed the virus.

Another problem: It won't let me update windows!

Are there any good, free programs to use to fix this or at least find out what's wronge? Thanks

If you have a XP disk I suggest doing a clean instal.

If you don't want to immediately go through reinstalling windows xp, I would suggest going here, reading through the instructions and posting your logs.

Hope this helps,