Airport card and Roadrunner Wireless Router

Question

I'm trying to network my girlfriend's iMac 350 with a shiny used airport card from eBay to her wireless roadrunner router, but whenever it tries to connect it says that there is a list which the iMac must be on in order to have access to the internet. I'll give the entire error message next time I get in touch with her and her computer.
I tried to get into her router configuration (or whatever it is where you put the router address as a URL) to find this elusive list, but she does not know her username or password for to get into the configuration.
I've tried hooking the mac directly to the router and modem and a couple of combinations therein, called RR tech support, who apparently don't know jack about macs, and managed to fry her router, which was replaced free of charge. I foundthis discussion which I will try next, though it is geared toward the airport base station, so it seems. http://discussions.apple.com/thread.jspa?messageID=607409&#607409
If anyone has had this problem and found a solution, I could really use some guidance

Answer 1

if the router is asking for a WEP key or for the iMac's M.A.C. address (that of the Airport card) for it to be allowed to communicate with the wireless then you need the password and admin information to the router.
Nothing can be done on the iMac's side to fix this.
The issue is with the router and how its set up its security functions to filter out computers not meant to be connected to it. You must add your iMac to the approved list or turn off the router's security functions.