If you've run a registry cleaner, that's the problem
CC Cleaner is a good utility program as long as you don't let it try to clean the registry. If you or your son did that, that's likely the problem. Registry cleaners are snake oil that do no noticable good and can cause problems that're extremely difficult to diagnose and resolve. Celeron processors are known to be slow. If I had a computer that'd had a registry cleaner run on it, I'd back up any data I wanted to keep and reinstall Windows.