Having a master domain controller running Windows 2003, and now I'd like to set up a new domain controller on a branch office. I really only have access to licenses for Windows 2008 R2 (through licensing.microsoft.com), so question is if a newly installed Windows 2008 Standard R2 can become a domain controller in the existing (2003) domain?
First I tried adprep /forestprep on the newly installed 2008, but it complained about not being a domain controller. I then tried dcpromo, but it too complained about it. According to MS documentation, it seems I have to run 'adprep /forestprep' on the master domain controller, and adprep is located in 2008 installation DVD.
Am I on the right track? Is the correct way to mount the 2008 installation dvd into the existing 2003 master controller, and run 'adprep /forestprep' on it there? Will I be able to run dcpromo on the 2008 once that has been completed?