In a forest, there are at least five FSMO roles that are assigned to one or more domain controllers. The five FSMO roles are:
If a computer no longer exists, the role must be seized. To seize a role, use the Ntdsutil.exe utility.
For additional information about how to use the Ntdsutil.exe utility to seize FSMO roles, click the article number below to view the article in the Microsoft Knowledge Base:
255504 Using Ntdsutil.exe to Seize or Transfer the FSMO Roles to a Domain
Use the Active Directory Schema Master snap-in to transfer the schema master role. Before you can use this snap-in, you must register the Schmmgmt.dll file.