Networking with XP

I have a similar problem as another user, however, my laptop is the host in a home network. It connects directly to an ADSL broadband Internet connection. My other PC continues to register with a private address, and thus is unable to browse files or connect to the Internet through my laptop. I also was unable to configure the PC to be the host instead of the laptop. Both systems are running XP Home edition. Thank you for any help you can give.