I downloaded Exchange 2013 Eval from technet but it failed trying to setup Mailbox role, I checked the version and it was RTM so I downloaded CU 9, after uninstalling and trying to install CU 9 I get errors at the prerequisite check and while trying to perform /preparead or /prepareschema:

the AD schema isn't up-to-date and this user account isnt a member of the "Schema Admins" and/or "Enterprise Admins"

Setup encountered a problem while validating the state of AD:  Couldnt find the Enterprise Organization container.

I am logged in as domain/administrator and that account IS both a schema and enterprise admin.  It seems to happen when you uninstall and resinstall after a failed installation as I was able to get further when installing for the first time...previously on the RTM release I had the same issue and wound up reinstalling exchange (new server) but got the Mailbox installation failure so I downloaded CU9 -- Exchange is on the same server as I've been asked to make it that way since they are only 10 users and have been using Exchange 2003 for years with AD on the same old server (they don't use AD though just WORKGROUP).  

Hi,

Similar thread for reference

https://social.technet.microsoft.com/Forums/exchange/en-US/391de462-e057-4ab2-9540-eb35c897d8b6/error-couldnt-find-the-enterprise-organization-container-exchange-install?forum=exchange2010

Best Regards.

Hi Mgnj,

Are you saying you are trying to install Exchange 2013 using the same AD which currently has Ex2003 in the environment. This is not a supported scenario and you woun't be able to do it.

Secondly if Ex2003 is currently not there and you have removed it, make sure there are no stale entries and the removal is complete.

If its a different AD server with no Exchange related contents then, most likely there has been some corruption or stale entires on the server due to the failed install and uninstallations. Try to remove those.

Hello, 

This didn't help me as the /forestprep is a depreciated command; I am not upgrading Exchange or AD -- starting from new on a 2008 R2 Server that was just reinstalled and updated -- no other programs or old software on it.  The issue happens when I am unable to install Exchange and then uninstall to try again.  It seems to be leaving traces of the old installation but I cannot proceed -- my only option is to uninstall AD and start again.  I have tried running c:\exchangesetup\setup.exe /preparead /iacceptexchangeserverlicenseterms and the other setup commands (prepareschema for instance).  

No, Exchange 2003 exists on another server, I am setting this up on a new server with Server 2008 R2 Standard.

• Edited by mgnj 14 hours 42 minutes ago

No, Exchange 2003 exists on another server, I am setting this up on a new server with Server 2008 R2 Standard.

• Edited by mgnj Friday, September 04, 2015 4:49 PM

No, Exchange 2003 exists on another server, I am setting this up on a new server with Server 2008 R2 Standard.

• Edited by mgnj Friday, September 04, 2015 4:49 PM

Hi Mgnj,

You didn't seem to have read my post correctly. What I'm asking, "Is Exchange 2003 in the same ActiveDirectory domain as the new Ex2013 server"

The exchange2003 server name and Ex2013 servername, is it ex2003.domain.com, ex2013.domain.com?

You don't have to /prepareforest, just run the /prepareschema, /prepareAD, /preparedomain one at a time.

Magically, after running setup again and getting different errors it has now installed and somewhat working.  I will post the details of troubles in another thread.  Thank you for your help.