How can i change the pitch of a song and burn it?

Okay, my sister has a dance competition coming up and she says that the song is just a little to fast for her to keep up with. I have already tried using the windows media player to try to change the pitch of her song and burn it to a cd but there seems to be no way how. I was wondering if there was any way that itunes or any other program out there, free please 🙂, could allow me to change the speed of any song and burn that changed song on to a cd.

This would make me so happy!

Windows XP