So my Active Directory setup is set to work for computers running Vista or higher. I didn't foresee the need to have a Windows Server 2003 computer on the domain, so how can I now be able to join the 2003 computer to the 2008 domain? Thanks
So my Active Directory setup is set to work for computers running Vista or higher. I didn't foresee the need to have a Windows Server 2003 computer on the domain, so how can I now be able to join the 2003 computer to the 2008 domain? Thanks
You can just join it to the domain. The domain functional level is only for the versions of Windows that can be domain controllers on the domain. You could join a Windows NT 4 machine to the domain if you wanted to.
If you mean how do you add a new Domain Controller running Windows Server 2003 after you've raised the Domain/Forest functional level to Windows Server 2008, the short answer is you can't.
If you just mean a normal member server, just go ahead and join it - it should work fine.
To add to @Mrdenny answer, the restriction applies to DOMAIN CONTROLLERS, not regular members.