Anyway, in Windows you have to let Windows to sync the music from iPod to PC. This is normally happens when you plug the iPod in to the PC, and the "what do you want to do with this device" dialogue pops-up. Its here you can choose to sync music. If you don't get the pop-up you've probably told Windows it to not bother you ever again with that dialogue. You can reverse that by going to My Computer, right clicking on the iPodís icon and somewhere in there is the option re-enable or manually run an import.
What's more, you can refer these tutorials about how to transfer music from iPod to Computer
Hope it can do you a favor.