All bets are off about repair. BUT TRY THIS. Create a new user account and see if it works right there.
So there was a virus of some kind in my pc. I deleted any kind of registry affiliated with it in the registry editor. But now when my PC is started, it doesn't automatically start the Windows Explorer, instead, it starts Command Prompt and when I put in explorer.exe there, everything starts normally and I have to close the Command Prompt. I saw online that the value of Shell key in winlogon has to be explorer.exe. I checked and it was explorer.exe. Yet still the problem persists. Any solutions?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic