Many restore errors can be solved by following the troubleshooting steps in this document.
Upgrade to the latest version of iTunes
To check whether you have the latest version of iTunes, open iTunes and:
* Windows: choose Help> Check for Updates
* Mac: Choose iTunes> Check for Updates
If there is an update to iTunes, install it and try to restore again. If you do not have an active Internet connection or Internet security settings are configured to prevent iTunes from communicating with Apple, iTunes will alert you that could not connect to the iTunes update server. Internet solves problems and try the update again. If you are using Windows, see this article.
Restart the computer
Only restarting the computer can solve certain problems that could prevent the restoration of the iPhone or iPod touch. After restarting the computer, try restoring the device again in iTunes.