No Network Connection

Hello,
I am trying to get a network connection up and running on a new network

at my mother's house. Previously they had one computer plugged
directly into a cable modem. The computer was running Norton Internet
Security as it's firewall application. They now have another computer
they want hooked up, so I plugged the cable modem into a Belkin
wireless router and the new computer into the router and bingo the new
computer works.

I plugged the old computer into the router and I get nothing. Not even

a light on the router indicating that there is a connection to the
computer. I plug the old computer back into the cable modem and it
works again. I am thinking that Norton might be hosing something up,
but I am not sure since I didn't set up that computer.


Any thoughts or ideas on what might be happening?


Thanks.