is this a work laptop that you are trying to connect to your LAN at home? if so, do not disjoin from the domain, and join your home domain (not sure why you would have one in the first place). this will cause headache for your tech support at work, and doesn't even do anything for you. you should be able to plug the network cable in, and get an IP. once you have an IP, you should be able to freerange the network.
if it's not a work computer, and you are just messing around setting up domains, then remove yourself from the previous domain, and join the one that is on your network. even so, you don't have to join the domain to get an IP and surf the net.