Error 1604: This error is often related to USB timing. Try changing USB ports, uninstalling and reinstalling USB ports, and other available USB troubleshooting steps (troubleshooting USB connections, device not recognized properly, computer won't recognize a FireWire or USB device). If you are using a dock, bypass it and connect directly to the white Apple USB dock connector cable. If the issue persists on a known-good computer, the device may need service.
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 error 1604.
- When prompted, click OK.
- Close and reopen iTunes while iPhone remains connected.
- iPhone 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.
This worked for me. I think the key was that I changed the USB port as well and followed instructions.
I shut the phone by pressing Home + Power. As soon as the phone shut down, I plugged out the iPhone and connected to another USB. While doing this, I also shut the iTunes.
When I followed the instructions of restore afterwards, it sailed through. Successful.
You are trying to install older iOS which Apple does not permit. If you update to newest iOS 6.1.2 and still get the error
Click at the link below and then browse to error 1604