This is my understanding of the matter. If I run: setup /PrepareSchema AND setup /PrepareAD /on:contoso In a single forest with a single domain (contoso.com for example), I do NOT need to run: setup /PrepareDomain Yet, I have seen others (on Exchange blogs or in articles) present that as a (necessary?) third command. Yes, yes, yes... I understand that if there are several domains, that third command needs to be run in every domain where Exchange servers will be deployed, or even where mail-enabled users will be present ( /PrepareAllDomains is another option here ). My question concerns exclusively a one domain forest scenario.

No you don't need to run, when you run setup /preapareAD it automatically prepares the domain from where you ran it. "Run setup /PrepareDomain or setup /pd to prepare the local domain. Note that you do not need to run this in the domain where you ran Step 3. Running setup /PrepareAD prepares the local domain." How to Prepare Active Directory and Domains http://technet.microsoft.com/en-us/library/bb125224(v=exchg.80).aspxJames Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Right James, that's a good reference and the one I was looking at myself. However, it was last modified a while ago so I was wondering if something might have changed or if it was "Best Practice" to do so anyway - but it does not look like it. I'll let others contribute if they want before closing this (with "Marked as Answer")

Not really it's the same. Note that when you run the Exchange install it runs all the necessary preps.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

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