WD my passport-backup deletion

I deleted the backup file from WD my passport.
but the files in cache are not getting removed…msg pops out…that the file name is too long…
when i try to rename those files…rename option is also not available…please help!
can anyone tell me how to remove those files?

How were those files backed-up? Did you try uninstalling the backup utility used?

i just deleted the backup
and then the remaining files