I have a 2003 server running as the only DC on a domain. Wish to add second DC using 2008 R2 operating system. Ran adprep /forestprep and /domainprep from the 2003 box and it completed successfully. Running dcpromo from the 2008R2 member server and it fails saying /forestprep is required first. Not sure what I'm missing here. The 2003 server is a 32bit OS. From what I understand this requires to run /forestprep using the 32bit 2008 dvd which is what I did. Could the problem be the fact that I'm introducing a 2008R2 server but used a standard 2008 dvd to run the adprep work?