Before you can introduce Windows Server 2008 domain controllers into existing Windows 2000 or Windows Server 2003 domains, you must prepare the forest and domains with the ADPREP utility. ADPREP.exe is a command-line tool that extends the Active Directory schema, and updates permissions as necessary to prepare a forest and domain for a domain controller that runs the Windows Server 2008 operating system.
insert ur 2008 cd in yr domain controller cd drive run the following
u must run : ADPREP /forestprep
then : ADPREP /domainprep
this will prepare ur 2003 dc to add 2008 dc
dont forget to raise ur domain and forest Functional Level to 2003 in win 03 server
add the 2008, then promote using dc promo
I tried to run /forestprep and it told me I can only run it on an AD server. But I can’t get any further with 2008 AD install because it wants /forestprep ran. What’s up wit that?
You need to run /forestprep on an existing domain controller. Then you can promote your 2008 server.