That "duplicate" is probably the MS OneDrive "mirror", and it can and does cause grief. This is why you are better off in something you create in the root of the C: drive yourself, such as "C:\Games", and then put your Steam Library folder in that. You do NOT want to be directly in the root with the Steam Library, due the potential for "accidents" (
), but you do not want to run the risk of Windows getting in your way - er, uh... you getting in Windows way... we must remember, it is King, judge and executioner all in one...