Add secondary domain controller to an existing site with windows 2003 server

Hello, I want to add a second domain controller to an existing site.  There is only one existing domain controller which is a windows 2003 server.  I am adding a windows 2008 server.  I am getting a message, - to install a domain controller into this AD forest, you must first prepare the forest using adprep /forestprep".  The ADprep utility is available on the Windows Server 2008 installation media inthe \sources\adprep folder.

Do I run this on the windows 2008 server?  It seems like I should run this on the windows 2003 server?  Please advise.
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Lee W, MVPConnect With a Mentor Technology and Business Process AdvisorCommented:
mnkhawaja is incorrect.

Your existing site has a 2003 server.  2003 has NO IDEA what changes were made in 2008 - THAT is why you must run ADPREP on the 2003 server.  ADPREP prepares the domain for the addition of a DC that is NEWER than the existing DCs.  Note: if the 2003 server is 32 bit and the 2008 server is 64 bit then you must run ADPREP32 on 2003 server.  You can't even run ADPREP on the 2008 system since it cannot be a domain controller until it joins the domain AS a domain controller and it can't do that until you run ADPREP on the existing old DCs.  (And even then, if you ran it on a DC of the same version, it wouldn't do anything!)
Mohammed KhawajaManager - Infrastructure:  Information TechnologyCommented:
You should run it from the Win2k8 cd on the win2k8 server.
manch03Author Commented:
I am not sure how to run adprep on the 2003 server.  I typed it into a command line, but it does not recognize it.
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Lee W, MVPTechnology and Business Process AdvisorCommented:
Where did you run it from?  You need to use the 2008 DVD and run it from the appropriate folder on the 2003 system.
manch03Author Commented:
I did a command prompt accessing the dvd drive files.
Seth SimmonsSr. Systems AdministratorCommented:
please clarify if you have 32bit or 64bit 2003 and 2008 as it will make a difference here
in 2008, the 32bit and 64bit versions of adprep are included in their respective media in the \sources\adprep folder; run adprep from a command prompt on the 2003 server

however, if this is 2008 R2 (which is 64bit only) then both 32bit (adprep32) and 64bit versions of adprep are included in the \support\adprep folder - which would need to be run on the 2003 server

here is an article that discusses the process more

you mainly want to focus on running it 3 times with these switches (one at a time in order):


the first 2 are required; 3rd is optional but required if you plan to use any read-only domain controllers
Lee W, MVPTechnology and Business Process AdvisorCommented:
If you are having trouble, please post the screen shot of the command prompt you are running it from.  If it didn't work, then you're doing something wrong and it would be SO much easier to direct you if you showed us what you're seeing.
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