CC Cleaner only deletes cookies and most recent temporary files, which is usually quite few. it's quite good to detect errors in the system though.
I recommend using Eraser. It deletes all temporary files definitely by rewriting over them and last time I used it my CPu's speed was doubled since it erased more than 30 Go of temp. Files!! And it's completely free!!
the best way to boost your cpu is either to change it ^^ or to buy some specialised stuff for it. These kind of programs exist and work really well but they are not really known as most person change their CPU ...
buy RAM. very useful stuff, ram. Used to know a really god site that checked ur PC's RAM and thne checked if you could fit any more ram in, then offered to sell you some that would work with your PC. But I forgot it. Not much use, am I? But look out for RAM chips, check the back of ur PC, and the instruction manual.
You can check for virus, defragment your disk drive, run hard disk cleanup, delete unnecessary files/folder/programs etc. I also believe someone else above me recommended CC Cleaner Also if you use firefox get the Add-on betterprivacy and delete your LSO cookies