Perform a reset of the iPod :
1) If you own an iPod 1G, 2G or 3G: Press the Menu and Play / Pause button until the Apple logo appears.
2) If you own an iPod mini, 4G, U2 or photo: press the Menu and Select buttons until the Apple logo appears.
Update the firmware of the iPod :
1) Download the software update for iPod: http://www.apple.com/fr/ipod/download.
2) Connect the iPod to the computer and start the software.
3) Use the Update.
Skip the iPod in Disk Mode :
1) Connect the iPod to the adapter.
2) Lock and unlock the iPod using the Hold button.
3) Perform a reset of the iPod.
4) Once the logo appeared, immediately press the Previous and Next buttons until the Disk Mode appears.
5) Disconnect the iPod from the area and connect to the computer.
Restore iPod :
1) Download the software update for iPod: http://www.apple.com/fr/ipod/download.
2) Connect the iPod to the computer and start the software.
3) Use the Restore function.
CAUTION: Restoring the iPod completely erase its contents, music and data.
-- Using an iPod on a Mac PC :
To do this you must format the iPod so that Windows recognizes it.