1) I suggest you download the free CCleaner and remove ALL junk files it finds. Then do the Registry clean. Be sure to do the Registry backup. I've used CCleaner for years and never had any problems with the Registry clean portion it has. I run it several times until no items are detected. You could use Windows Tools to clean files and remove old restore points.
2) No single program can find all malware. I would suggest you start off with AVG 2013 (free) and a full disc scan. Then Malwarebytes Anti-Malware (free). Be sure to run Root Scans, too. These guides may help you with other suggestions.