How can i tell whats junk on my computer, i think there might be worthless files and programs on my computer but i dont where to find or delete them, Ive gotten rid of the obvious ones, but there might be some in my temp folder or in the windows folder

Can i delete stuff from my temp folder, cause disk cleanup doesnt work.

I downloaded this thing called Easy Cleaner which helps clean out the registry and some useless files

just wondering