I have an isolated test environment that mimics my production environment. We have only one existing Exchange 2003 server. My virtualized test environment looks like this: DMZ: Exchange 2003 box, Win2008 box (for Edge Transport server role, not installed yet) Private network: Windows 2003 domain controller, XP client machine & Windows 2008 box (for Exchange 2007) Public network: XP client machine Custom built linux Firewall (I am not the firewall expert, that's a coworker, who assures me this is set up properly) The Exchange 2003 installation works. While running the ExBPA (in both test and production environments), I get errors accessing the domain controllers: Active Directory server: WMI cannot be accessed. Cannot connect to the Windows Management Instrumentation (WMI) repository on server servername. This could be the result of a network or permissions problem. Error: The RPC server is unavailable. I've read this thread with good info, but no results: http://social.technet.microsoft.com/Forums/en-US/exchangesvrdeploy/thread/fe94ece1-6701-4936-b604-9c5c0114fe58 It is not a permissions issue that I can tell. I am a domain admin (double and triple checked) on all boxes. I am also a domain admin in my live environment on all servers. The firewall is not blocking any RPC communication or other ports that I can identify as necessary to this process. I have also been reading that this may not be that big a deal, if my existing installation is working fine (which it is) and some people have gone on to successfully install Exchange 2007. SO, in my test environment i have attempted that, but get errors at the first attempt to do the /preparelegacyexchangepermissions step. I've read that I can get around that by running the installation on the 2003 domain controller to make the AD changes, but it really feels like I am duct taping this install, and I want to do it properly. So, is the WMI issue causing my installation error, and I need to start there to resolve? I can attach log files, if they are needed. Any assistance is greatly appreciated.

Check info: 1. Why you put an exchange 2003 server in the DMZ? Since theres no exchange server in the private network, based on your description, could you remove this exchange server? 2. You have an exchange 2003 server in the DMZ, and the exchange 2007 hasnt been installed on the windows server 2008 in the private network, right? Please correct me if I have misunderstood the topology 3. Do you get this same ExBPA error both in the lab and product environment? 4. Have you tried the steps of the link in the thread that you mentioned? 5. Please use the Troubleshooting WMI Connectivity Issues section in Microsoft Exchange Server Best Practices Analyzer Tool Troubleshooting Connectivity Problems Quote: Regardless of where you run the setup /PrepareLegacyExchangePermissions command, Setup must be able to communicate with an Active Directory directory server that is running Windows Server 2003 with Service Pack 1 or later 6. Whats the service pack of your windows server 2003 DC? 7. Which server did you run the command on? 8. Whats the error info that you got after run the command? Is there any related event in the application log? Please also check the installation log for related error info Notes: Which kind of virtualization software do you use? We shall use Microsoft supported virtualization environments. Microsoft has three software offerings, Windows Server 2008, Microsoft Virtual PC, and Microsoft Virtual Server; or we can use the 3rd-party products on the SVVP list Resources: Preparing Legacy Exchange Permissions Microsoft server software and supported virtualization environments Support policy for Microsoft software running in non-Microsoft hardware virtualization software