Você deve remover manualmente o controlador de domínio antigo do diretório ativo e, em seguida, instalar o novo.
Primeiro, verifique as funções do fsmo - executadas em um shell de cmd elevado
netdom query fsmo
E mova funções do fsmo que estão no DC com falha para o DC em execução
Em seguida, remova o DC com falha do diretório ativo:
Step 1: Cleaning up metadata via Active Directory Users and Computers
- Log in to DC server as Domain/Enterprise administrator and navigate to Server Manager > Tools > Active Directory Users and Computers
- Expand the Domain > Domain Controllers
- Right click on the DC server that need to remove manually and click delete
- In next dialog box, click yes to confirmmeta3
- n next dialog box, select This Domain Controller is permanently offline and can no longer be demoted using the Active Directory Domain Services Installation Wizard (DCPROMO) and click Delete
- If the domain controller is global catalog server, in next window click yes to continue with deletion
- If the domain controller holds any FSMO roles in next window, click ok to move them to the domain controller which is available
Step 2: Cleaning up the DC server instance from the Active Directory Sites and Services
- Go to Server manager > Tools > Active Directory Sites and Services
- Expand the Sites and go to the server which need to remove
- Right click and click Deletemeta5
- In next window click yes to confirmmeta6
Step 3: Clean up metadata using ntdsutil
- Right Click on Start > Command Prompt (admin)
- Type ntdsutil and entermeta7
- Then metadata cleanupmeta8
- Next type remove selected server , replace with DC server to removemeta9
- In warning window click yes to proceed
- Execute quit command twice
citado de: Passo-a-Passo: Removendo manualmente um servidor de controlador de domínio