I can get internet on one computer, but not on the other

I have one computer that connects to my router via ethernet cord and another that connects with a wireless card. the router and card are both from netgear. Both computers run windows XP. It used to work fine, now I can only get internet on one of the computers no matter what I do. If i reset everything (modem, router, computers) the first computer to turn on gets the connection and the other one won't work. Also I can only access the router through the laptop. I've updated the firmware, but the desktop still won't log on to the router. I've tried my cable company and Netgear and neither will help me. Please help.