sharing DSL connection between XP users

I finally got DSL and everything works great when I'm on my desktop. I'm running XP and when I log onto my wife's desktop I can't connect. I've called my ISP about it but they said that I have to set up XP to share the internet connection between users. I'm having a hard time doing this. I've fumbled around looking for how to do this but I can't figure it out. Any and all help is much appreciated.