Hi all I have small simple organization. One forest-one Domain (Windows 2003 Native) Two Domain controller - windows 2003 R2, One Exchange 2007 Sp2 Server with MBX,CAS,HUB roles. When i installed Exchange Sp3 i get error "Summary: 5 item(s). 2 succeeded, 1 failed. Elapsed time: 00:09:02 Hub Transport Role Completed Elapsed Time: 00:01:54 Client Access Role Completed Elapsed Time: 00:01:44 Mailbox Role Failed Error: Could not find the Exchange Mailbox Administrators Universal Security Group through its well-known GUID d998d80b-0839-4210-b77b-f4a555e07fa1. Please make sure that Setup /prepareAD has been run. Elapsed Time: 00:05:22 Management Tools Cancelled Finalizing Setup Cancelled " After that i try run /prepareAD for fix this issue, but i receive another error " The following server roles will be installed Mailbox Role The following server roles are already installed: Mailbox Role. Setup previously failed while performing the action "BuildToBuildUpgrade". You cannot resume setup by performing the action "Install". Exchange Server setup encountered an error. " KB http://support.microsoft.com/kb/947281 isn`t fix problem It`s wery strange problem. Maybe anything fixed similar problem ?

Remove the Watermark from this registry location HKLM\Software\Microsoft\Exchange\v8.0\<name of role>. for each role find and delete the Watremark key MCP, MCSE 2000 , MCSA 2000 ,MCSA 2003 , MCITP , MCTS , MCT