I will demote a domain controller by PowerShell on Windows Server 2012.
Assuming that there is 1 domain controller named DC01 in "contoso.com" domain.
1. On DC01, log in as Domain Administrator.
2. Launch "PowerShell".
3. Perform "Test-ADDSDomainControllerUninstallation -LastDomainControllerInDomain -RemoveApplicationPartitions | ft -Wrap".
4. Provide a new local administrator password.
The status is "Success".
Remark: Before the domain controller is demote, we can perform "Test-ADDSDomainControllerUninstallation" cmdlet to runsome prerequisites check in your domain environment. "Test-ADDSDomainControllerUninstallation" is a new cmdlet in Windows Server 2012.
5. Perform "Uninstall-ADDSDomainController -LastDomainControllerInDomain -RemoveApplicationPartitions".
6. Provide a new local administrator password for DC01.
7. Enter "Y" to continue with this operation.
Now, DC01 is demoting the AD DS. When the demotion finished, DC01 will restart automatically.
As a result, DC01 was demoted.
Remark: To force removal a domain controller by PowerShell, perform "Uninstall-ADDSDomainController -ForceRemoval -DemoteOperationsMasterRole".
This posting is provided “AS IS” with no warranties, and confers no rights!
