Are you sure there's still incomplete files in drive C. Check Drive F & you may find another incomplete folder there. I must say I haven't explored this option too many times, but in my experience the incomplete folder seemed to follow the Audio folder (same parent folder.) But the older incomplete folder will still be on C drive but the files will have been moved to the new location.
If not, then perhaps you may need to move another of the folders to F or G also. Or as a last resort, move the entire Shared folder to another drive, then splinter them off onto the other drives.