If you use your computer very often, then you are sure that you are copying and pasting many files from one folder to another. The problem arises when you no longer remember the copies you have made and therefore you have the same files repeated throughout the hard drive.
This redundancy of data for the only thing that is useful is to have the hard disk more saturated, and therefore the computer is less efficient and its performance is getting worse.
Therefore, it is always interesting to have a tool like Duplicate File Hunter which tracks your hard drive in search of duplicate and repeated files to eliminate them, being the user the one who decides if finally the list of resulting files is deleted or not.
You can free download Duplicate File Hunter 32, 64 bit and safe install the latest trial or new full version for Windows 10 from the official site.