What else is there? ip,subnet mask,name?

What else is there to do when I change the ip address,the subnet mask and computer names in a network. Network is W2k server,pro and xp workstations.Network is have some issues.
I know how to change all these items but? Am I missing any other changes? Does the registry need to be changed?I plan to disconnect the network and make all the changes then reconnect as a workgroup then promote again via dcpromo after I demote my domain controller. I don’t know if the dcpromo is a good idea or not? I feel I’m missing something what do you think?
I will award 500 points for the best answer. If you know how to award partial points let me know just in case I get several good ideas. I will try to be fair to more than one good response.