Loss of DHCP Server access

I have a small network sharing a cable modem through a router. The router failed and I had to replace it. The new router would not accept the IP Address for the ISP DHCP Server. It kept coming back as IP Address 0.0.0.0.

I was using my XP Pro machine for the router set-up.

After disconnecting the router and connecting my machine back into the cable modem, my XP Professional would not access the internet. Attempts to renew the IP information with IPCONFIG/release and then IPCONFIG/renew met with a timeout error, saying the DHCP Server could not be located.

My WIN 98 laptop and ME desktop can still access the internet when connected directly to the cable modem. Where would the DHCP IP Address be hard coded in XP, when the network profile is set to automatically obtain an IP Address?

Thanks,