Keep asking to restore...(nano 1st gen)

Hi,

I bought a new 1st nano (4GB) for my girlfriend, she didnt charge the ipod at the first time ( she just plug it in the computer and put the musics in it).

There was no problem occured at the first day she used it. On the next day, the ipod played the music not smoothly and she pluged it in the computer , then the itune kept asking to restore the ipod. (window kept asking to format too)

I tried many ways but none of them works.

(cannot format, restore, or change disk letter...)

Here is my situation:

http://km.support.apple.com/library/APPLE/APPLECARE_ALLGEOS/TS1441/TS1441_3.jpg

http://img.photobucket.com/albums/v309/chester1027/Ipod%20problems/windowscantfo rmatF.png

http://img.photobucket.com/albums/v309/chester1027/Ipod%20problems/aftermakeanew simplevolume.png

http://img.photobucket.com/albums/v309/chester1027/Ipod%20problems/33.png

http://img.photobucket.com/albums/v309/chester1027/Ipod%20problems/22.png

http://img.photobucket.com/albums/v309/chester1027/Ipod%20problems/11.png