My Passport SE wont back up Mpeg files any help

I have some old Mpeg Files transfered them to my new PC when I try to back up WD smartware says partial back up and indicates that these files are not backed up can anybody help Thank You

mpeg is supported

make sure no other application is using the files

you can try a file backup  instead

Usually the partial backup message appears when one of the programs in your computer is using the files, it could even be an anti virus scanning the computer, just leave it alone and the backup should complete.