How to Convert a Mac iPod to a PC iPod
- 1). Launch iTunes, then connect the iPod to the computer using the included USB cable or dock connector.
- 2). Click "OK" if you are prompted to install a software update for the iPod. You will not actually be able to install an update, as the iPod is formatted for the Mac. However, the next screen will prompt you to restore the device to its factory settings.
- 3). Click "Restore," then click "Restore" again when you are asked to confirm the operation. When this process is finished, you will be prompted to set up your iPod's partnership with iTunes as if it were a new device.
- 4). Enter the name that you would like to use to identify your iPod, and select whether you would like media to be updated automatically on the iPod, or managed by you manually.
- 5). Click "Next," then click "Done." Your iPod is now ready to use.
Source...