Like the saying goes...I know my pc like the back of my hand :p.
I have CCleaner but that program is useless or I just don't have the problems that the program is searching for.
The only things that the program find are things that are recreated really quickly...like mru or unused file extensions and junk like that,nothing that can be considered a problem(like missing dds,activex problems,applications paths and so on)
I don't use such programs and every time before I install something,I first check it on a virtual pc to see what will install,what it will change in the registry and what it will auto start with windows