http://blogs.technet.com/exchangept/archive/2009/05/21/ocs-front-end-service-fails-to-start-after-kb967831.aspxKB967831 patch will try to update OCS and afterwards will try to start RtcQmsAgent (aka Monitoring Agent) If you dont use or configure this service it will never start, causing the rollback of the patch and with it the failure of the frontend service.en-USCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.technet.com/exchangept/archive/2009/05/21/ocs-front-end-service-fails-to-start-after-kb967831.aspx#3247602Fri, 29 May 2009 19:20:27 GMTd5e57398-b9ef-4490-9955-07cbb4e4a80d:3247602Gus<p>I guess I'm not sure why Microsoft doesn't have a mechanism that checks to see if MSMQ is installed on the front end server or not.</p> <p>Should also have something on the <a rel="nofollow" target="_new" href="http://support.microsoft.com/kb/967831">http://support.microsoft.com/kb/967831</a> web site that says to install MSMQ first.</p>