Adding backup domain controller to Windows 2008 domain

Our current domain controller runs Windows Server 2008. Tried to add a second domain controller that runs Windows Server 2008 R2 to the domain and I get a message saying that I have to run adprep first, using the command "adprep /forestprep" (please see attached image). Is this expected? Current DC is not R2.
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Cliff GaliherCommented:
Yes, that is expected, and yes you must upgrade the forest and domain schema before you can make a 2008 R2 server a domain controller.

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Seth SimmonsSr. Systems AdministratorCommented:
you also need to run adprep /domainprep after /forestprep

run adprep32 if your 2008 server is 32bit
Brian PiercePhotographerCommented:
Yes - its a simple process

Put the 2008R2 disk in the existing DC (if it autoruns then abort).

Then run from the sources folder on the DVD run
adprep /forestprep
this may take a few minutes, then run
adprep /domainprep
this will only take a few seconds
bobox00Author Commented:
Thanks for your comments. I plan to now upgrade the server first, to Windows 2012. Will it be the same process?
Brian PiercePhotographerCommented:
You will not need to run adprep again - 2012 automatically does adprep in the background.
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Windows Server 2008

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