Demoting a PDC

For the demote PDC command to be active you must have another PDC or BDC in your network. If the other PDC is boot up, the active PDC should automatically demote itself.

Hi, you cannot demote a PDC to a BDC without a BDC present. You would need to back up everything on the PDC that is offline now and reinstall nt server as a BDC. Connect it to the network, run a full synchronization (from server manager)and then promote the BDC to a PDC. Only during a promotion will you be able to "demote" the PDC. Hope this helps.

When you bring the currently-off PDC back online, you will get a service fail message because there is already a PDC online. Demote the machine you just brought online to BDC. If this is the setup you want, you are done. However, if the machine you just brought online is the one you want to be the PDC, re-promote it to PDC and it will force the current PDC to become a BDC.

This is a lab in the MS Admin course 803. when you will turn on your old PDC it will realize there is already a PDC, therfore it will be greyed out in server manager, the menu is contextual when you select the grey PDC it will have a choice of demote to BDC this will also syncronize the directory database if any changes have been made, then simply promote this BDC(oldPDC) to PDC and the temporary PDC will return to as before. there is no automatic recovery.

Good luck

Gaston Durand, MCSE, MCT

sorry, I was thinking of something else. You can do what you want by bringing the PDC back online. You will be able to demote the PDC that is online now to bdc status. It's a good idea to do this when you can run a full synchronization on the network.

The only way to "demote" a PDC is to have both PDCs turned on - at least one of them will then display the "Demote" option (ILO the "promote" option) in server manager. By defintion, you always need one Primary Domain Controller - you cannot run with only BDCs. The way you'd get two PDCs at once is: Real PDC goes down. You promote BDC to 'acting' PDC. Real PDC is fixed. Real PDC will then want to come back to be the PDC: As the real PDC was down when it happened, it will have no record ofthe BDC's promotion in its - the primary - security database. Only the acting PDC will have a record of its own promotion - thus knowing that it is due for a demotion again.

To make the acting PDC the permanent PDC, demote it for now. Then, from the 'real' PDC, in server manager, promote the BDC to be the new PDC. That way the transfer of power is recorded in both servers' security database.

See Microsoft Article Q167248. To demote the original PDC just brought back online, use Server Manager. Under
the View menu, clear the check box next to "Show domain members only." This
allows a browse list to inform Server Manager that the computer is configured as
a PDC, and will allow it to be demoted. Select the original PDC, and select
"Demote to backup domain controller" under the Computer menu.

It seems you installed the 2nd domain controller without the connection. You need to installed the 2nd one after the router and proper connection. Than only you can demote & promote any domain controller.
I think you need to upload the full operationg system with the connection.

If your PDC went off-line before promoting a BDC, the registry entry on the PDC which governs the server role was not changed.

When you bring the PDC on-line, it comes up as a PDC. When it finds that another computer is the PDC, it simply stops its' NetLogon service. The only way to fix this is to edit the registry at:

HKEY_LOCAL_MACHINE\Security

Choose Security / Permissions and insure that Administrators have Full Control on this key and all sub-keys. Navigate to:

HKEY_LOCAL_MACHINE\Security\Policy\PolSrvRo and change the value entry from 03000000 to 02000000

where the 3 indicates Primary and the 2 indicates Backup.

Shutdown and restart Windows NT on the old PDC. It will restart as a BDC which you can then promote.

I hope that helps a little.

Thanks,
Jasjeet Singh

Corky,

Bring them both up, after the second one sees the other PDC they will both demote themselves, allowing you the chance to promote the one of choice. (I hope you choose the one with the most recent changes to the SAM)