the best way I have found for a good general computer cleaning is to download ccleaner. I have apps on this computer trying to block as much of the adds as well as blocking most cookies from sites and there is still a bunch of junk that collects in just a week or two so its good to run ccleaner regularly.
piriform.com/ccleaner
It is a free ( or you can buy a better version of it) piece of software that does a good job of keeping the computer junk to a minimum. It will also allow you to do a register sweep and repair as well as other things.