WS2016: Demote Domain Level

less than 1 minute read

Description:

Follow these steps to demote a WS2016 DC to a 2012r2 domain so 2012r2 DC’s can join the domain.

To Resolve:

  1. Open Admin PS on the domain controller and type:

    (Get-ADForest).ForestMode	
    Set-ADForestMode -ForestMode Windows2012r2Forest
    (Get-ADForest).ForestMode	
    (Get-ADDomain).DomainMode
    Set-ADDomainMode -DomainMode Windows2012r2Domain
    (Get-ADDomain).DomainMode
    
  2. You really only need the two Set- commands, I just put the others to see the before and after – look at the properties before and after you change them!