So I was overclocking my E5200 here and there, and my computer was continuously freezing due to incorrect voltages. So the only way to go was shut down the computer. However, on one of the bootups, I received an error message which simply would not go away (it was CI.dll or something)
So inserted my vista OEM cd, and went through startup repair. After it was completed, another error appeared. System repair. After several errors and system repairs, I finally got the computer to go past the loading screen... but now it is just restarting after the loading screen is finished.
Note: After the computer restarts, and boots again, I get a "Start windows normally, etc." page. I individually selected all the choices, but they all lead to a system restart...
Did you find out what was causing and have you corrected the voltage issue? If not, that would be a necessary first step before attempting anything else. If you have, then it's likely that the bad voltage caused a lot of file corruption. You're probably looking at a complete reload to get it up and running properly again.
I had same problem last week on my 64-bit vista ultimate and solution was simple; I installed CCleaner and selected all options (windows explorer, system, advanced) to clean it, after that cleaned registry. After reboot everything is working perfect