This could be because your software isn't compatible for Windows Vista.
I've looked on Philips site for any software for that mp3 player and campatible with Vista, but i had no luck.
Have you tryed connecting it to your computer and using Windows Media Player 10 or 11 to add your songs. If now and you want to try go to Media Player 10 or 11 which ever you have if you haven't got a latest version download here http://www.microsoft.com/windows/windowsmedia/player/11/default.aspx
When you've successfully installed media player 11 you've opened media player 11 at the top click on the link called "Sync" once you've done that if your mp3 players been connnected it sshould show a little mp3 player in the top right of the pane.
Now to add music yu simply drag and drop the music you want on your mp3 player to where it says "Drag items here" once you've done that just click on "Start Snyc" at the bottom.
Good luck. Hope my solution was helpful in some way. Further problems just leave a comment on this page and i will get back to you a.s.a.p.