1: Disconnect your device from the computer.
2: Turn off your device by holding down the power button and then sliding the red slider.
3: Press and hold the Home button while reconnecting the device to your computer. When reconnected, your device should turn on.
4: Continue holding the Home button until you see the "Connect to iTunes" screen on your device, with a picture of a cable, an arrow, and an iTunes logo.
5: If iTunes is open or you opened it to use it, you will see the following message displayed on the iTunes screen.