Unable to demote a domain controller

Question

Hi Everone,
My primary DC is windows Server 2012 R2 and ADC is windows Server 2008 x64
I am trying to demote  Windows Server 2008 x64 and i am facing issues.
when i demote2008 I am getting Error : A Domain Controller could not be contacted for the domain(mydomain.com) that contains
an account for this computers.Make the computer a member of a workgroup then rejoin the domain before retrying the prmotion.
The specified domain either doesnot exist or could not be contacted
When i browse my \\windows2012dc i cannot see sysvol and netlogon shared folders.
on window2012dc C:\windows\sysvol\mydomain and mydomain folder is empty.(no issues with replication in sites and services and no issues with connectivity or gateway )
please guide me because i dont want forceful demote.

Answer 1

I would first recommend taking backups of both DCs before proceeding with any changes.
Before trying a forced demotion, you can try the following:
Make sure that both DCs have a single NIC card enabled and only one IP address in use
Make both DCs point to the other as primary DNS server, their private IP addresses as secondary DNS server and 127.0.0.1 as third one. Once done, run
ipconfig /registerdns and restart netlogon service
Disable any security filtering between both DCs and temporary disable security software you use
If this does not help then you need to proceed with a forced demotion.
You can then proceed like the following (First, Use dcdiag to check that the Windows Server 2012 R2 DC has no problems apart of the SYSVOL folder and the replication with the other DC):
Shutdown the DC running Windows Server 2008 (Do not bring it online again without re-installing it later)
Seize all FSMO roles to your Windows Server 2012 R2 DC if it is not already the current FSMO holder: http://support.microsoft.com/KB/255504
Do a metadata cleanup to remove the data of the old Windows Server 2008 DC: Use
dssite.msc to remove its NTDS settings and object over there then use
dsa.msc to remove its AD account
Rebuild your SYSVOL tree: http://support.microsoft.com/kb/315457
This posting is provided "AS IS" with no warranties or guarantees , and confers no rights.
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