Raise Domain and Forest Function Level

Question

Hello All,

I am currently in the process of migrating my company's servers from Windows Server 2012 to Windows Server 2019.

However I am unable to upgrade the Domain and Forest function level.

It seems to be locked at Windows 2000 level

Any help would be greatly appreciated
Thank-you

Answer 1

Please run;

Dcdiag /v /c /d /e /s:%computername% >C:\dcdiag.log
repadmin /showrepl >C:\repl.txt
ipconfig /all > C:\dc1.txt
ipconfig /all > C:\dc2.txt
ipconfig /all > C:\dc3.txt

then put unzipped text files up on OneDrive and share a link.

Answer 2

Any progress or updates? A likely reason is there are remnants of old failed or removed domain controllers. You can do cleanup to remove the remnants.
https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/deploy/ad-ds-metadata-cleanup
https://techcommunity.microsoft.com/t5/itops-talk-blog/step-by-step-manually-removing-a-domain-controller-server/ba-p/280564

--please don't forget to upvote and Accept as answer if the reply is helpful--

Answer 3

Hi，
Welcome to share here!
To know the issue more clearly, please help confirm the following information.

1, Based on my understanding, Windows server 2000 level supports only the following Domain Controller Operating System:
Windows Server 2008 R2
Windows Server 2008
Windows Server 2003
Windows 2000
2, Since you said there are 2012 domain controllers, it will be at least 2003 level.
If possible, please tell more details about your environment.
Such as the all the versions of the DCs
Domain and forest function level
And make sure everything runs well by command.

Following information for your reference:
Upgrading from Windows 2000 Domains to Windows Server 2003 Domains
https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2003/cc781198(v=ws.10)?redirectedfrom=MSDN

Best Regards,