unable to renew IP

I have a laptop running on XP I’m trying to connect to internet. I’m on Cox Cable. I changed to a new router so I could use wifi. I have a desktop that is currently connected to router and there is no problem so I know that the router and modem are working fine. I’m trying to connect the laptop with cable and keep getting a message telling me that windows could not renew my IP.
So I used a command prompt and entered: “ipconfig/renew” and this message came up:
“An error occurred while renewing interface Local Area Connection : unable to contact your DHCP server.”