Hi Tom, You don't need to install SP1 first, you can install SP2 directly. Suggest you uninstall Exchange 2010 SP1 mailbox role first, after that, do Prepare Active Directory and Domains again, and install SP2. By the way, as I know, /PrepareAD only creates the Discovery Search mailbox's user account, Exchange Setup will enable the mailbox for the accout. For more information, please see: Re-Create the Discovery System Mailbox http://technet.microsoft.com/en-us/library/gg588318.aspx Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.Frank Wang TechNet Community Support

Hello, I am in the process of installing MBX role on a Windows 2008 R2 cluster. It is a new installation and the media I used is Exchange 2010 with SP1. Installation failed with errors related to Discovery Search mailbox. Before installing MBX roles, I have Exchange 2010 CAS/HT roles running on seperate machines with NLB thus I completed prerequisites like setup.com/pl, setup.com/ps, setup.com/p, setup.com/pd and I assume /p created this Discovery Search mailbox. I updated this CAS/HT to SP2 before trying to install MBX roles. I deleted "Discovery Search Mailbox" and reran Exchange 2010 MBX role installation. It completed the installation succesfully. I also update this machine with SP2. Now I need to recreate "Discovery Search Mailbox". Can I run setup.com/p from this new MBX server with Exchange 2010/SP2 and will it create the "Discovery Search Mailbox" properly? TIA Tom

http://social.technet.microsoft.com/Forums/en/exchange2010/thread/290ebc15-e30a-4636-98f9-3b61c75e41b0 Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Hi Tom, You don't need to install SP1 first, you can install SP2 directly. Suggest you uninstall Exchange 2010 SP1 mailbox role first, after that, do Prepare Active Directory and Domains again, and install SP2. By the way, as I know, /PrepareAD only creates the Discovery Search mailbox's user account, Exchange Setup will enable the mailbox for the accout. For more information, please see: Re-Create the Discovery System Mailbox http://technet.microsoft.com/en-us/library/gg588318.aspx Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.Frank Wang TechNet Community Support

Hi Tom, Any updates?Frank Wang TechNet Community Support