So my question is, why will it not clean?
There is would be few answers
1 you got virus in temp folder like a trojan. download Unlocker 1.85 go to temp folder and remove those files
2 look on [#] tray notification cache. It is look like you hot somethink on right down side of your screen
Make sure you close all run programm befor run CC, and you'll see it would clean lot of thinks