A W2K desktop defaults to DNS for name resolution. You could try removing any reference to a DNS suffix for the computer or the interfaces. This will prevent the machine from constructing a fully qualified domain name to submit to DNS.
If you have quite a few hosts on your local network, you should set up a DNS server and make it authoritative for you local zone. Then you can forward Internet names to the ISP server.
If you don't have many hosts on your local network and you don't want to fuss with DNS, you can put a HOSTS table on the machines. The Windows client checks HOSTS before querying DNS.
This was first published in May 2001