For anyone who can’t get their computer to recognise an iPod plugged into a USB port, the likeliest solution is to reset the iPod. This won’t remove any files from the iPod, though some settings may be lost. Here from the Apple website is how to do it, although the title, Resetting iPod if it appears frozen or doesn’t respond, is misleading as your iPod may actually be working fine. Anyway:
- Toggle the Hold switch on and off. (Slide it to Hold, then turn it off again.)
- Press and hold the Menu and Select buttons until the Apple logo appears, about 6 to 10 seconds. You may need to repeat this step.
That should do it.