music transfer from ipod to computer

I am trying to transfer music from my ipod to my computer. I was following the instructions I found on-line, but when I connect the ipod to the computer and open it in My Computer, I don't get an Itunes folder. I get a folder labelled metadata never index. This happened w/both my ipods. So where is my Itunes folder now? I have a 4th gen Nano and a 6th gen Nano.