I'm on Windows 7 right now due to some kind of miracle, but otherwise, today I spent all day trying to repair it.
It will not start successfully, it is very unstable and gives me the error 0x00000051, an error Microsoft associates only with Windows 2000 and XP.
It's also clearly a registry error, according to the numerous BSODs I got today. Do you guys recommend I fix my registry with a specialized registry repair tool or something?
If it helps, it was running like a champ and the last thing I did before it became unstable was install a game. Virus scans don't show anything out of the ordinary.