I have setup a new 2003 R2 64bit system with SP2 fully updated. I am then doing all the prerequisites that is needed before installing exchange 2007 enterprise edition.When I run {setup /p /onomain name} I get the following error-----------------------------------------------Performing Microsoft Exchange Server Prerequisite CheckOrganization Checks .............COMPLETEDConfiguring Microsoft Exchange ServerOrganization Preparation ......FAILEDActive Directory operation failed on SERVER.MYDOMAIN.com. The object 'CN=All Contacts,CN=All Address Lists,CN=Address Lists Container,CN=COMPANY NAME,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=NAME,DC=com' already exists.The Exchange Server setup operation did not complete. Visit http://support.microsoft.com and enter the Error ID to find more information.Exchange Server setup encountered an error. Any assistance will be appreciated.

Is your domain already prepared? Or are you trying to prepare the domain with a different orgname?

It's an existing Win2003 Domain with an existing Exchange 2003 Org. We want to add the Exch2007 Cluster into the existing Exch Org.