Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

My network design is hub and spoke, all offices connected to HQ. Each office has a backup domain controller which replicates with my PDC. All DCs are running Windows Server 2003. I plan on upgrading my PDC to Windows 2003 R2 and then to Windows Server 2008. Do I need to upgrade all the other DCs at the same time? If I upgrade to WS2K R2 only, can I upgrade the others at a later date?

share|improve this question
up vote 5 down vote accepted

You can join an Windows Server 2008 domain controller onto your Windows 2003 Active Directory domain as it sits. You won't be able to change the "Functional Level" of the domain or forest to Windows 2008 until you've upgraded all the Windows 2003 DC's.

share|improve this answer

You should be fine upgrading the DC. Just be sure to not Upgrade the operational mode of your AD until all servers are at the same level.

share|improve this answer
Attempting to upgrade the domain/forest functional level to Server 2008 while there are still Server 2003 DCs will simply fail & tell you why it can't be done. – ThatGraemeGuy Jun 23 '09 at 17:56

I added a Windows 2008 Server as a secondary domain controller about six months ago without problem. My primary domain controller remains a Windows 2003 Server. I did, however, upgrade the operation mode of our active directory as Zypher mentioned.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.