MP3 Player

I have an MP3 player that when you sync it using Windows Media Player, the songs are loaded and you could see the display of the MP3 giving you the information regarding the songs, but there is no audio. No matter how many times you download the music to the MP3 it simply do not work. Another thing it does is that when you hit the play button, the songs start to jump over (still no sound) but they jump since you can see the timer going from 0:00 to 0:14 to 0:26 and so on until the song ends and the next starts. Anyway, there is absolutely no sound from the device. Could you help me to identify and solve the problem? I gave this MP3 as a present to my son and he has not been able to use it yet. The instructions says that the device do not any driver if my operating system is above Windows 98se and I have Windows Vista and it still does not work. Thank you for your assistance.