Exchange 2010 SP3 failed in the Organization Preparation steps ? Share on Facebook Post on reddit Tweet on Twitter Share on LinkedIn Home › Forums › Messaging Software › Exchange 2007 / 2010 / 2013 › Exchange 2010 SP3 failed in the Organization Preparation steps ? This topic has 10 replies, 2 voices, and was last updated 5 years, 5 months ago by albertwt. Viewing 1 post (of 1 total) Author Posts albertwtMember Dec 22, 2014 at 6:27 pm #164687 Hi All, I need your experts advice in how to resolve the problem in installing the SP3. I’m executing the Setup.COM /PrepareAD command from my Schema Master DC with the elevated command prompt under my user account (which is a member of Enterprise, Domain and Schema admin group). Somehow the installation always end up in Organization Preparation FAILED step. the following error message is the detailed error when I look through the ExchangeSetup.log file: Quote: [ERROR] Active Directory operation failed on. The object ‘OU=Microsoft Exchange Security Groups’ already exists. [ERROR] The object exists. [ERROR-REFERENCE] Id=443949901 Any kind of help and suggestion to help me get through this error would be greatly appreciated. Thanks. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic.