If you've run a registry cleaner, that's likely the source of your problem. They do no noticeable good and can cause problems. Whatever the cause, I'd back up any data you want to save and prepare to restore your computer to factory settings.
Good luck.
My computer won't start after Windows 7 critical update 1/11/13. I was able to start in safe mode and restore to an earlier date. However, that only worked for 1 day. Now it won't connect to wireless either. Any suggestions?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic