I began my quest to "transition" to Exchange 2007 this morning. I ran the Exchange Best Practices Analyzer and cured all of the Critical Issues (I never even noticed any of the others). I began the process of installing exchange 2007. The first command setup.com /PrepareLegacyExchangePermissions went fine and the org check and prep work succeeded. I moved on to the setup.com /PrepareSchema and my hopes of this being easy died a horrible deathI received an error message stating that this time the Organizational Check Failed. It seems that one of my 2 DCs are running Win2k SP4. Cant Exchange 2k7 just use the Win2k3 DC to conduct business? In the Exchange BPA tool, it states that it just wont use the Win2k DC, but according the the PrepareSchema command, it won't even update AD's schema. Has anyone had success deplying Exchange 2k7 in an environment with a mixture of Windows 2k and 2k3 DCs?It may help to note that I switched the Schema Master from the 2k server to 2k3 server this morning. Would that be the likely problem here?PS It states to use the error code given to get more info from support.microsoft.com, but there is no error code on the screen or in the Event Viewer.

Exchange will quite happily use only the Wind2k3 DC provided it is the Operations Master for the AD FSMO Roles which are required for Exchange to Operate & a Global Catalogue server. Check the FSMO Operations Masters, Transfer them to the 2k3DC if necessary, Make the 2k3 DC a GC then try the schema update again. Allow for replication to occur and if required restart the servers. Also make sure your domain is in Native Mode If it still fails you can add the /dc:2k3dc.domain.com switch at the ent of the setup command to force it to talk to your 2k3 DC.