Good morning. We have root domain (tp.ru)and controller (Windows Server 2003 x86)for this domain. Exchange 2003 organization is installed on it. Also we have another domains, that are in one forest with root domain. Exchange 2003 is installed on this controllers and are in one Exchangeorganization. and I have a problem with Exchange 2007 SP1 installation: Error:Setup needs to contact the Active Directory schema master but this computer is not in the same Active Directory site as the schema master (tgroup).Recommended Action: http://go.microsoft.com/fwlink/?linkid=30939&l=en&v=ExBPA.3&id=2376fec1-b9ce-44db-beb6-cb9ac4788988 Error:Setup needs to contact the Active Directory schema master but this computer is not in the same Active Directory domain as the schema master (DC=tp,DC=ru).Recommended Action: http://go.microsoft.com/fwlink/?linkid=30939&l=en&v=ExBPA.3&id=2376fec1-b9ce-44db-beb6-cb9ac4788988 Error:Setup encountered a problem while validating the state of Active Directory: Exchange organization-level objects have not been created, and setup cannot create them because the local computer is not in the same domain and site as the schema master. Run setup with the /prepareAD parameter on a computer in the domain tp and site tgroup, and wait for replication to complete. when I try setup /prepareAD on the domain controller of the tp.ru domain, an error is occured "Exchange Server 2003 is installed" how can I install Exchange Server 2007in my domain, which is in the same forest with root domain (schema master, site tgroup)

Try this System where you installing EXCH07 has only internal DNS. Update OS from MS site Run setup.com /prepareAD from your new system for EXCH07