so im copying data, program files, games ect. from my hdd on my external hdd so i can put them on my new hdd im going to get. but the problem is, is that theres 64.3gigs left on the external hdd and when i try to copy a file thats around 6 gigs to the external hdd it says it cant copy because theres not enough space. The external drive is an 256GB(or so) external western digital with 64.3gigs unused. whats wrong?