Auslogics Duplicate File Finder (click) Searches for audio, video, images, archives (e.g. .zip), and programs. Search on name and/or date-time and/or file size. Optionally will create an MD5 hash of each file and then compare 'em all, finds dupes even if they aren't named the same - as music files often are (or aren't as the case may be). Windows only, XP, 2000, Vista, Windows 7 (and Server 2000, 3, and 8). 32 & 64 bit versions available. $ Free (as in beer).