I have been involved in a server migration from SBS 2003 to Windows Server 2008 r2, Exchnage 2003 to Exchange 2010
Everything seemed to be going well until we got to the stage of turning off the SBS server.
It seems for some reason that its not recognising itself as a domain controller. There should be a 2nd server in that attachment image called fileserver.
I have not been able to get it to show up at all. so everytime I turn off the SBS server I am unable to access the exchange console and mail stops working