How to change Forest Functional Level and Domain Level?

Note:

Make sure you have Enterprise Admin account/permission to run this command and run the PowerShell as Admin. 

If you run into error that you can’t bring up a new Domain Controller due to Operating System is not in the suitable forest functional level, this solution could help you out. RODC is not accepted to run these commands.

I am not sure whether does this require FSMO roles to make the changes towards these functional levels. Hence, I run these commands on the Primary domain controller.

1. Login to your existing domain controller using an enterprise admin account
2. Run the Windows PowerShell as Admin
3. Type in the following command to change the forest functional level

   • #Get Forest level Info
     Get-ADForest
     
     #To Set the forest level
     Set-ADForestMode -ForestMode <Operating System Name>
     
     #Example: Set-ADForestMode -ForestMode Windows2012R2Forest

4. Type the following command to change the domain level

   • #Get Domain level Info
     Get-ADDomain
     
     #To Set the forest level
     Set-ADDomainMode -DomainMode <Operating System Name>
     
     #Example: Set-ADDomainMode -DomainMode Windows2012R2Forest

Would recommend that you study on the difference between Forest Functional Level and Domain level. I would write a blog post about it soon!

Author: sabrinaksy

Just a little girl who love what she does best. View all posts by sabrinaksy