Or on a usb drive?
Most Helpful Guy
It depends on what you want. A hard drive has a limited life, but pictures will still be on it and will still be recoverable, even if the mechanism has failed. The only way to delete it for sure is to use a secure file shredder. Then use a slack space eraser.
A picture on a usb drive will last as long as the drive works, and may still be recoverable if it fails.
To really destroy them for good, you have to strip the hard drive, remove the platters and melt them with a blowtorch. I think most are made of metal coated glass, so be careful! Similar with usb drive. Really want to delete them, destroy the drive, crunch up the chips with big wire cutters.0
Most Helpful Girl
Forever or until the device dies/craps out...1