Use Active Directory Migration Tool to migrate computer accounts from a source domain to a target domain. While migrating, users can retain access to resources on the computers. Once all of the computers and resources have been migrated, the source domain can be decommissioned. Before performing the migration, you can test the process without actually migrating the accounts by clicking Test the migration settings and migrate later in the wizards.
Domain controllers cannot be moved between domains. Windows NT domain controllers must either be upgraded to Windows 2000 and, in the process, joined to the target domain or, you must reinstall Windows NT. Windows 2000 domain controllers can be demoted to member servers, joined to the target domain and promoted to domain controller in that domain. Any domain local groups referenced by security descriptors on the domain controller to be moved must be moved before the server is moved.
Workstations and member servers have their own security account manager (SAM) databases. When they are moved between domains, their SAM database moves with them. Local user and group accounts are not affected when moving a computer.
When migrating computer accounts from Windows NT domains, Active Directory Migration tool will not migrate computer descriptions because the computer description attribute is not stored in the Windows NT domain SAM. The description is stored on the local computer. Active Directory Migration Tool will migrate nonnull computer descriptions from computer accounts in Windows 2000 source domains.