Double File Scanner can scan for, and delete, duplicate files on your hard drive based on SHA-1 hashes.
Double File Scanner does not scan all of Windows by default but asks you to choose a folder or folders that you want to scan. This can be handy for finding duplicate images, videos or documents. Optionally you can also recurse subdirectories as well, which is ticked on by default. If you change your mind or make a mistake, you can remove a directory or clear all directories.
While scanning, there's a progress bar going left and right as well as a magnifying glass icon that spins yet neither one gives you an accurate progress indicator. If you change your mind, you can press ESC to cancel. A cancel button might be helpful here.
Double File Scanner gets the job done fairly quickly. We decided to scan our entire C: drive as a test, and we gave up after 10 minutes. Of course, odds are you're not going to scan your entire drive, and that's not what it was designed for.
Once the scan has completed, you are shown any duplicate files. We placed the same file, with different names, on my desktop and it found the duplicate immediately and within seconds. You can then open, go to, rename or delete any files presented by right-clicking or using the Edit drop down. Under the File drop down you can clear, Automatic Clean-Up (delete all but one), copy to clipboard, and export duplicates list.
Double File Scanner works as advertised. It's super fast and free.