Using 2 Ipods with same I Tunes

Hi
Could someone give me the key ??? We have 2 ipods at home, one nano that does work correctly and a second one Shuffle second generation that is neither recognized by windows (everytime i connect it it asks me to install it but the shuffle does not have a pilot ...) nor by Itunes. What can I do to make it work as well as the other one. I've tried lots of ways but none are working... Please help !!!! Thanks