You have recently acquired a used, or second-hand, iPod, from a friend or store that sells Apple products. If you only acquired the second-hand iPod, you will need to purchase another item to connect that player into a PC. Once you have done this, you might need to change one of the settings on the second-hand iPod. Doing so will allow you to use the second-hand iPod with the iTunes library that's on your PC.
Acquire an Apple USB cable for the second-hand iPod if you don't already own one.
Connect the Apple plug-in end of the USB cable to the Apple port on the iPod.
Plug the USB end of the same Apple cord into one USB port on your computer.
Click the iPod name located in the “Source Pane” underneath “Devices.”
Click inside the tab labelled “Summary” at the top of iTunes.
Click on the box that's found directly next to “Manually manage music and videos.” Then, click the “Apply” button located near the bottom of the program to save this setting.