ISP DHCP shutting down internal DHCP

Our ISP just installed a DHCP server (we won’t be using it, we have static IP address for internet). Our NT box has two NIC cards, one for local network, the other connected to our cable modem. It has DHCP server running for our local workstationsto get their ip addresses. But it has been shutting down with an error message stating that “The DHCP server is shutting down because another DHCP server with IP address of 172.29.0.2 is active on the network.” 172.29.0.2 is our ISP’s new DHCP server. How can I get our server to ignore the ISP’s DHCP server?