Domain upgrade scenarios
In a domain upgrade, you convert a Windows NT® domain controller to an Active Directory domain controller. During an upgrade, the primary domain controller is unavailable briefly.
These topics describe several scenarios in which one or more Windows
NT® domains are upgraded to Active Directory domains by using the in-place
upgrade procedure defined by Microsoft. If your site is not using
this procedure, see Domain migration scenarios.
Note: References to upgrading a domain refer to upgrading the primary
domain controller of that domain.