Re: Need a utility to compare contents of 2 external hard-drives
I wonder if this might help you?
What they say: "The program is incredibly fast; after a minute or two, one can see how many duplicate images are stored and how much disk space will be saved by removing the duplicates. The "dupes" can then be removed all at once with a single click. Alternatively, a user can specify which images need to be deleted, moved or copied." http://www.bolidesoft.com/imagecomparer.html
Maybe the free version will highlight the duplicates even if you can't remove them with one click.
"I want to die in my sleep like my grandad, not like his passengers - screaming."