Transferring Files From iPod Touch to Windows P.C.

I'm trying to transfer some songs that were downloaded from another computer onto my iPod Touch to my Windows P.C. I follow the steps listed online up to the point where I have connected the iPod to the P.C. and have to use "file sharing" and select which apps I want to share files from. When this option comes up, however, there are no apps to select from. Does anyone know how to fix this, or another way to upload my music from the iPod to the P.C.?