Make sure you have the latest version of iTunes installed.
Disconnect the USB cable from the iPhone or iPod touch dock connector but leave the other end connected to your computer.
Power the device off,
either how you normally would,
or forcing it to power off by holding the lock and home buttons.
Press and hold the home button while connecting the USB cable to your device`s dock connector.
If you see the low battery screen wait about 10 minutes for the device to charge and then restart this process.
If you don`t see the above image continue holding the home button until you see the connect to iTunes screen.
You may now release the home button.
iTunes should now display the following recovery message,
if not quit and reopen iTunes.
If you still don`t see the recovery message repeat these steps again.