You can analyze the whole drive or set several specific folders, but beware of the filters the program uses as default, as they may sort out folders that you want to include in the scan. The process takes a while, but in exchange for your patience the program delivers a complete list of all duplicate files in your system. This list also offers a preview of each file, so you're sure of what you're going to delete before marking them.
Duplicate File Detector works with a wide range of file formats and can detect duplicates based on a large variety of criteria. In fact, there are so many configuration settings that it may feel a bit overwhelming at the beginning.