Unfortunately, there is no one ‘Silver Bullet’ answer for this issue. Many things can contribute to the problem. Here are various ‘generic’ solutions that you can try in an effort to correct your problem. One should work. These are listed in simplest to more involved order (usually).
First, make sure that the iPod is fully charged.
Try
Resetting Your iPod
while it's connected to the computer.
Hold down the Menu and Select buttons until you see the Apple logo (or Menu & Play/Pause in older models).
This will often get it recognized. It may take several attempts.
Try closing and re-starting iTunes. There have been cases where iTunes refuses to see an iPod, but after re-starting, it works again.
Also try re-booting the entire computer. Especially if the PC has been operating for a long time &/or many programs have been opened and closed, repeatedly.
Other USB connected peripherals may be the cause as well. Try removing
all connected USB items and attaching the iPod. If you have a USB keyboard, it may be worth a try using the adapter to convert it to non-USB. If the iPod connects, continue plugging things back in until you have the problem return. You may have then isolated the issue. Sometimes it could be a printer, camera, Flash Card reader, or other attached device causing a conflict.
If your iPod shows up in Explorer under 'my computer' try changing the drive letter:
-- Click on Start=>Control Panel=>Admin Tools=>Computer Management=>Disk Management
-- Right-Click on the iPod and select “change drive letter”
-- Choose something further along in the alphabet that is unused (Usually, “M”, “N”, “O” or something similar)
-- Safely eject the iPod
-- Reboot the PC
If that doesn't work,
Put Your iPod into Disk Mode then plug it in and you should be able to
Restore the iPod
Your PC may have difficulty with the USB2 protocol and the iPod. See this Article for a possible solution:
iPod not Recognized Correctly
Also try these hints (and the other suggestions above) from any other USB port you may have on the PC. Sometimes switching USB ports can make all the difference.
Also See:
Your Windows PC doesn't recognize iPod
iPod does not appear in iTunes or on the desktop
iPod appears in Windows Explorer but does not appear in iTunes“Strange iPod Behavior within Windows”
