This program has a feature to find dupes, but it doesn't say it goes past Win XP
EasyCleaner

Getting dupes in drag 'n drop is 'usually' a matter of whether you hold down the 'shift' key or not. Sometime you want a 2nd copy in another folder. Since I forget, or miss the key, I usually use the above mentioned FreeCommander to do moving of files, although if I am in IrfanView image viewer, I will often use its very nice system ..(it will let you drag OR just designate a folder and click a 'move' button.)

I used to have on an old computer, a program for finding duplicate images by checking various stuff from size to color patterns, but I almost never used it as it was slow when asked to 'look hard', so I never added it to this PC.