Well, you're using xp, so make sure the firewall feature is disabled on the realtec network interfaces on each machine. Were you able to connect to the Internet OK from the host machine? I assume this machine has 2 network cards in it. It should be able to get out regardless of what you do with the other interface and the other computer. You can do an IPCONFIG /all command from the command prompt on each machine and let me know what they say. Be specific. ICS should use the DNS information it gets from the Internet connected Interface, which you haven't said, but I believe is probably automatic.