wow, i see three post with the same title. Anyways. like ken said. there aren't technically. if you just want to clean a files. you can used windows disk cleanup. Other program might interfering with your registry which is dangerous and you might ended up posting another thread in here
I have seen so many posts caused by reg cleaner. If you want to clean your system, follow Kens advice and do not use it. Ocassionally, you can use cclenaer, without the reg option. http://www.piriform.com/ccleaner
As an alternative, you can just use Windows Search. It has customizable filters that let you search by filetype. E.g. if you want to look for all pictures on drive X:, just navigate to to X: in Windows Explorer and type kind: pictures (no space between : and p) in the search box at the top right. Then you can delete what you think are duplicates. That is the safest way, IMO.
If you are thinking of searching for duplicate files with regards to music/pics/docs etc then glary utilities has a neat little function which searches for such things and then gives you the option of ascertaining which you would like to remove.
If you are on about reg cleaners then take the above advise from the other forum members and leave it alone, it is very efficient at managing itself.