Useful for finding duplicate images, photos because this app has image preview and thumbnails bar. You can check for duplicate music files also by using Mp3 bar.

Here are the steps to find and delete duplicate files.

Step 1: Download Duplicate Finder (Link Below)

Link : http://www.ashisoft.com/downloads/dfsetup.zip

Download Duplicate Finder to a known location. Run setup and follow on-screen instructions to install the application.

Step 2: Launch the program.

Step 2: Add locations where want to look for duplicate files.
You can add paths with criteria e.g. Include sub-folder, file types, file sizes and date range.

Step 3: Select the Search Engine.
Select the Search Engine e.g. Byte by Byte, CRC32, Same File Names, and Zero Size.

Click “Scan” button to start the search.

Now the program starts searching. It can take some time, depending on your system and on the number of files in the selected folders. Also some searching algorithms are more time consuming than other. You can just minimize the program and let it run in the background.

Step 4: Review Searched Result.
After search is completed, you should review search result to verify if they are duplicates by previewing images, opening files and folders and view file properties.

Step 5: Mark the files you want to Delete / Move / Copy
It is possible to review all the files and check duplicates manually, but Duplicates Finder is also able to remove duplicates automatically. You can click the corresponding button to do this.

By default, the Duplicate Finder move files to the Recycle Bin. This way, you can easily restore them, if something useful is deleted. Let a few days pass before emptying your Recycle Bin. Until then the space will not be recovered, but there’s a better chance that you will find out if something is missing.

It can find duplicate files and duplicate directories
plus many other features

I have tried it but still finds Duplicate Finder is better.

Clone Tools works with folders containing duplictae files instead of just a long list of all duplicate files as in most (or all?) other duplicate file finders. I think this gives you a better overview of your duplicate content.