- If you are updating via wifi on the iPod then try connecting to your computer and update fia via iTunes.
- If you updated via iTunes then
Place the iOS device in Recovery Mode and then connect to your computer and restore via iTunes. The iPod will be erased.
- If recovery mode does not work try DFU mode.
- Try on another computer
- If still not successful that usually indicates a hardware problem and an appointment at the Genius Bar of an Apple store is in order.