http://blogs.technet.com/b/nawar/archive/2010/08/19/exchange-2010-rtm-schema-prep-fails-with-exchange-2007-sp3-installed.aspxProblem: When planning to deploy Exchange 2010 RTM Schema in an Exchange 2007 environment that is running SP3, you will encounter the following error: “ Setup encountered a problem while validating the state of Active Directory. Theen-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)