If you want to use iExplorer on a PC with a Mac formatted iPod, you'll need to use an app called MacDrive in conjunction with iExplorer. You can download the free 5 day trial by going to the link below and click on "Try it Free" under MacDrive 9 Standard:
Without it, a Mac formatted iPod won't connect to iTunes on a PC, and the only option in iTunes will be to reformat the iPod which will delete all of it's data. iPods are formatted based on which operating system you used to set it up and sync it. If you use Windows, it’s formatted as FAT32. If you use Mac, it’s formatted as HFS+. While iTunes on a Mac can read both, iTunes on a PC only works with FAT32 (Windows) formatted iPods.
Once MacDrive is installed, just open it, connect your device, open up iExplorer, and you should see your iPod appear and ready to transfer (though it might display as a different iPod model).