How to get rid of duplicate files

noshobawolf_f994bf986d

My laptop decided to have issues forcing me back to my old desktop. Unfortunately in the switch over from 3 to 4 I really screwed up my content files. How do I get rid of the duplicates and get them to condense into one? I am hoping they will be able to fix my laptop or at the very least retrieve my data . The gen 2 stuff was not out when I bought my laptop so they are nice and neatly organized.