ADPREP does not permit forest and domain preparation on Windows Server 2003 Beta 2 Active Directory Domain Controllers. Status/Consequence ...

ADPREP does not permit forest and domain preparation on Windows Server 2003 Beta 2 Active Directory Domain Controllers.
[Status/Consequence]
Upgrading from Beta 2 is not supported.
[User Action]
You must run Adprep on a server running Windows Server 2003, Windows Server 2008, or Windows Server 2008 R2.