Disks - badly damaged - if you have a badly damaged disk that your Mac won't accept, use the Finder to eject any disks in the drives. Look carefully at the right-hand side of the disk drive slot, you should see a small black lug next to a metal pin. Carefully press the lug down. Your Mac will think you have inserted a blank disk and will ask if you want to initialize it. Insert the bad disk into the slot and click the Initialize box.
