Please help! My Monster in Law changed the password on her i-Pad and then forgot what it is. I am trying to do a restore on i-Tunes. I keep getting a message that restore could not be completed Error 21 or Error 1604. I have tried 12 times now, please advise.
If the issue is not resolved by USB isolation troubleshooting, and another computer is not available, try these steps to resolve the issue:
- Connect the device to iTunes, confirm that the device is in Recovery Mode. If it's not in Recovery Mode, put it into Recovery Mode.
- Restore and wait for the error.
- When prompted, click OK.
- Close and reopen iTunes while the device remains connected.
- The device should now be recognized in Recovery Mode again.
- Try to restore again.
If the steps above do not resolve the issue, try restoring using a known-good USB cable, computer, and network connection.
Copied from Apple's article about specific iTunes error codes.