Sorting out unique files within 500GB of data

[dbrent]

I am looking for a program for Windows 7 (free preferable) that will sort through multiple backups that I have and save out only the unique files. I have over 500GB of data, but am guessing it's in reality about 150GB of data or so, once you eliminate the multiple copies of files over and over throughout the directories. This is mostly pictures, but there are other general files in this as well. Suggestions?

 

[CoryJ]

CCleaner has a duplicate finder under "tools." Check only the "size" and "content" boxes and that should take care of a good chunk of it.

 

[dbrent]

CCleaner has a duplicate finder under "tools." Check only the "size" and "content" boxes and that should take care of a good chunk of it.

Oh, it finds them, but this is not practical to sort through tens of thousands of duplicates. I need something that has a more robust feature-set outside of check a box to delete. I'd have carpel tunnel after this.