If your iPod classic does not appear in iTunes when you connect it to your computer, the USB drivers may be disabled or out of date. Without this connection, you will not be able to access your iPod through iTunes or add and remove files on the device. Enabling and updating the USB drivers on your computer can rectify this problem.
Connect the iPod to an available USB port on the computer using the iPod's USB cable.
Exit out of iTunes if iTunes automatically launches. Click on the Windows "Start" menu.
Click on "Run" in Windows XP or click on the "Search" box in Windows Vista and Windows 7. In the text box that appears type in: "devmgmt.msc" and press "Enter."
Wait for the Device Manager screen to appear. Scroll down the list in the right column until you see "USB Serial Bus Controllers."
Click on the small "+" sign icon next to "USB Serial Bus Controllers." A list of controllers appears.
Look for "Apple Mobile Device USB Driver" in the list and right-click on it. If you do not see this item, look for "Unknown" from the list and right-click on this selection.
Click on "Enable" from the menu that appears. Right-click again on the selected driver and select "Update Driver Software."
Wait for the update screen to appear and select "Search for New Drivers" if prompted. Select the option to scan all available options, including online, and click "Next." Click "OK" or "Finished" when prompted.
Launch iTunes and wait for the iPod icon to appear in the left side of iTunes under "Devices." Click on the iPod icon. Click on "Update" in the right side of the iTunes window.