I have something somewhere which is awesome - lets you set parameters to decide what makes 2 files duplicate - like name, filesize and even content (or any combination thereof). It doesn't actually delete anything, it moves them to a "possible duplicate" folder where you can examine the 2 files side by side to see if they are the same - if they are pics then you get a thumbnail of each...
Only thing is, it's on a portable HDD which is at work! :bonk: I'll get someone to access it and get it's name on Monday as I am out of the office all week.