Adding remote Server 2k8 DC to SBS2003 Domain

[Jimathy]

So here's where I'm at;

I have an SBS 2003 located in a DataCentre, have run adprep /domainprep & adprep /forestprep from a Windows Server 2008 CD.

I've successfully joined the Windows Server 2008 machine to the Domain but when I try to dcpromo I get an error saying I need to run the first two commands on the Domain Controller.

FWIW there are 3 other Windows Server 2003 machines located at other offices which I haven't run the adprep /domainprep /forestprep on. Do I need to do this?

TIA

 

[Jimathy]

Yes ran the adprep commands without issue. The SBS2k3 machine is set as the primary dns in the 2k8 boxes nic settings.
Scratching my head on this one.