ALSO get "CCLEANER" (with two C's- Probably also available at cnet)
CCLEANER is open-source software, therefore it's FREE!! And it's GREAT!
It gets rid of orphaned files, and registry errors, and other junk.
Just "scan for issues" (it will find a LOT) and hit "Fix Issues" and let it do its thing. It has never caused me a problem, and really gets all that junk that's bogging you down out of your way.
When it offers to let you make a back up, do it. You wont need it-I never have, but be safe. It has a few different types of scans it does, so do them all, and worry not.
It was recommended to me by a good friend who works for a big computer company, and he knows his stuff.