Using HDM2011S but probably this can be said about other products also. I'm making differential backups to a external USB drive. After a while I want to delete some older archives to regain disk space. You have the option to delete an archive but it's a not a physical deletion of the archive on the HD itself. Unless I've missed it, there's no way do this from within the program. Really, I don't see the point of the delete option available but maybe I'm missing the concept??