What do you do if you cant add anything to your friends ipod?

ok. so i can download videos to my laptop to my ipod. My friend wants me to add videos to her iPod so i connect it but all that comes up is "Ipod" nothing else i cant add anything to it! It says "I tunes has detected a Macintosh-formatted iPod. You must restore iPod.." what should i do!!!!!!!???????