dupeGuru is a free and open source tool to find duplicate files on your computer. It can scan either filenames or contents. The filename scan features a fuzzy matching algorithm that can find duplicate filenames even when they are not exactly the same. dupeGuru runs on Mac OS X, Linux, & Windows.
Finddupe is a tool for quick detecting of duplicate files on a hard drive under Windows. Duplicate files can be detected, hardlinked, or deleted. Finddupe can also search for hardlinked files on your computer.
Finddupe is a command line program. If you arent familiar with the "command prompt" under windows, this program might be a little challenging for you to use.
Finddupe has several possible uses:
Deleting duplicate files When working thru somebody elses photo collection, or MP3 collection, this tool is useful for deleting the files that are duplicate. Depending on how the media is organized, there can be a lot of duplicate files in a collection.
Freeing hard drive space Sometimes its intentional to have certain media in multiple places. By running finddupe, and hard linking the identical files, you can keep the files in multiple places, while only having one physical copy on the hard drive.
Detecting changed files for backup Finddupe is useful for detecting which files have changed and need backing up. Simply back up the media, and then run finddupe to eliminate those files in the copy that are already contained in a previous backup.
Detecting hardlinked groups of files Unknown to most, the winodws NTFS file system has the ability to hard link files together. If you use finddupe with the -listlink option, finddupe will search for files that appear in multiple places as hard links.
Symlink Creator simplifies the process of creating symbolic and hard links in Windows 7 and Windows 8 (likely Vista too). It is a GUI for the MKLINK command in Windows, which makes creating the links much easier.
The program requires administrator permissions due to use of the command prompt, so you should run it as an administrator if you experience any problems.
Note: It is not possible to create a hard link from a network share. You must use a symbolic link instead.
Most hard disks contain quite a lot of completely identical files, which consume a lot of disk space. This waste of space can be drastically reduced by using the NTFS file system hardlink functionality to link the identical files ("dupes") together.