If you have not already installed DUFF, then please see installation.:
To run DUFF:
Select the Windows Start button.
Select All Programs.
Select Sean Ryan.
Select DUplicateFileFinder.
The DUFF application will start.
DUFF will search a given location, for duplicate files.
DUFF will then move the duplicate files, to a location of your choice.
Later, you can decide if you want to delete the duplicate files.
note: DUFF does not delete any files.