Make sure you have downloaded and installed the latest version of iTunes on your computer before attempting this:
(Mac users can run System Preferences > Software Update (or “Apple Store” for OS X 10.9 users) > Check now to get the latest version for their system in most cases.)
Disconnect all cables from your Apple device.
Open iTunes on the computer
Turn off the device (press the sleep/wake button on the top until you see the red slider and slide the red slider across to the right OR until the device simply shuts off, if locked up).
Press and hold the Home button. While holding the Home button, connect your device to the computer running iTunes. (If your device doesn't turn on automatically, turn it on.)
Continue holding the Home button until you see the Connect to iTunes screen.
iTunes will alert you that it has detected a device in recovery mode. Click OK, then restore the device.
It may ask whether you wish to restore a backup from iTunes and you should choose this option to recover data from your last backup.
Ok, please try this alternative;
* Open iTunes on your computer and connect the Apple device directly to it
* Turn off the Apple device (press the sleep/wake button on the top until the device completely shuts off).
* Hold down the sleep/wake button (on the top) AND the home button (on the front) for 10 seconds
* Release the sleep/wake button but CONTINUE to hold the home button, until...
* iTunes should pop up and tell you it’s found a device in recovery mode, click OK and continue along for the restore.
Note: When you are in DFU mode the device's screen will be completely black.
If it doesn’t work the 1st time, restart your computer and start from the beginning and try again. If iTunes *still* doesn't recognize the device, restart once more and plug it into a DIFFERENT USB port and again.
Ok good luck!
Please let me know if you have further questions.