Error 6: All of the steps in this article apply to resolve this issue. Following iTunes for Windows: Troubleshooting security software frequently resolves this error. There may be third-party software installed that modifies your default packet size in Windows by inserting a TcpWindowSize entry into your Registry. If your default packet size is set incorrectly it can cause this error. Contact the manufacturer of the software that installed the packet size modification for assistance.

Error 9: This error occurs when the device unexpectedly drops off of the USB bus and communication stops. This can occur if the device is manually disconnected during the restore process. This issue can be resolved by performing USB isolation troubleshooting, using a different USB dock connector cable, trying another USB port, restoring on another computer, or by eliminating conflicts from third-party security software.

Error 13 and 14: These errors are typically resolved by performing one of more of the steps listed below:

Perform USB isolation troubleshooting, including a different USB port directly on the computer.
Put a USB 2.0 hub between the device and the computer.
Try a different USB 30-pin dock connector cable.
Eliminate third-party security software conflicts by following iTunes for Windows: Troubleshooting security software.
There may be third-party software installed that modifies your default packet size in Windows by inserting a TcpWindowSize entry into your Registry. If your default packet size is set incorrectly it can cause this error. Contact the manufacturer of the software that installed the packet size modification for assistance.
Connect your computer directly to your Internet source, bypassing any routers, hubs, or switches. You may need to restart your computer and modem to get online.
Try to restore from another known-good computer and network.
If you find an ASR error 1000 in the iPhone or iPod updater log file, that is an error decompressing and transferring the IPSW file that is downloaded during the restore. This error is frequently caused by third-party security software interference, a poor quality Internet connection resulting in a bad IPSW download, or a conflict on the USB bus.

Error 23, 28, 29, 1011, 1012, 1611: These errors may indicate a hardware issue with your device. Follow the steps in this article and also attempt to restore while connected to a known-good computer and network to isolate this issue to the device. If the IMEI or MAC address is missing or is a default value, this can also confirm a hardware issue.

Error 48: To resolve this error, follow the steps in this article. Also see the steps in “Restore using a new user account” above for .ipsw file locations.

Error 1015: This error is caused by attempts to downgrade the iPhone or iPod touch’s software. This can occur when you attempt to restore using an older .ipsw file. Downgrading to a previous version is not supported. To resolve this issue,use Tiny Umbrella or REC Bot


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 USB 30-pin 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 iPhone 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 re-open 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.

Error 2000-2009: If you experience this issue on a Mac, disconnect third-party devices, hubs, spare cables, reset the SMC, and then try to restore. Learn how to reset the SMC. If you are using a Windows computer, remove all USB devices and spare cables other than your keyboard, mouse, and the device, restart the computer, and try to restore. If that does not resolve, try the USB issue-resolution steps and articles listed for Error 1604 above. If the issue continues, it may be related to conflicting security software.

Error 3000-3999: Error codes in the 3000 range generally mean that iTunes cannot contact the gs.apple.com server on ports 80 or 443. This may be because out-of-date or incorrectly configured security or firewall software is interfering, or due to your Internet proxy settings. If you are using a proxy, try without using one or with a known-good network. If that does not resolve the issue, follow iTunes for Windows: Troubleshooting security software issues.

Error 3004: If the steps listed in Error 3000-3999 do not resolve, you may be able to resolve an error 3004 by quitting iTunes and using the following command at the command line: dscacheutil -flushcache

Error 9807: If you see “Error 9807″, open access to the following VeriSign servers:

evintl-ocsp.verisign.com
evsecure-ocsp.verisign.com
Error 9808: Follow the steps in iTunes Store: Unknown alert error message when connecting to resolve the issue. If those steps do not resolve the issue, or if the settings revert to their original values after the restart, then follow iTunes for Windows: Troubleshooting security software issues.

Via [Imodzone]