What is this shredder of which you speak? I have a 32gb SD card used in a dashcam that is now full of apparently undeletable mp4 files. All the usual methods haven,t managed it (delete, format full and quick, change attributes). Copying other movies after a delete without refreshing seems to work - copied files play while others are still being copied but as soon as the copy process is finished, they vanish and the old stuff reappears. I then remembered CCs drive wiper and decided to try it. 3 passes, nearly 36 hours and the drive shows empty. Refresh and everything is back again.Its not just a table of contents thing, the files actually play. Any help or suggestions would be helpful!