set up a trust between the two domains so that the users will see the new domain in the "Log on to" box at the logon screen.
configure a policy for the new domain that applies a logon script that runs the "netdom" command to join the computers tothe new domain. apply this policy to the domain.
when you are ready to move the computers, have your users logon to the new domain. the "netdom" command will run if the policy is set up correctly, and your computers should then be in the new domain. just keep in mind that the users will have to have local admin rights to change domain/workgroup settings for the machine, and you will need to reboot the machines for the settings to take effect. these can be done with the logon script as well.
this solution werx. i werk for a company that is in the middle of a migration right now (50,000+ users, multiple NT4 domains migrating to a single Win2K domain). also, may i suggest leaving the NT4 domain online until you are certain there are no problems with the new one. its good for your users to be able to log on to the old domain in case they have problems accessing resources with the new account. my company won't take the old NT4 domains offline until we finish migrating resources.
also, you should add your users' NT4 SIDs to the SID Historys of their new accounts in Active Directory. this ensures that either account has access to resources, i.e., if give permissions to the user's NT4 account, his Win2k account also hasaccess. the trust between domains must be inplace though...
hope this helps.
K