After migrating from SBS 2003 to SBS 2011, Exchange 2010 was working well. After 20 days I uninstalled Exchange on the old server, ran dcpromo to remove active directory and things still ran well. Then I rebooted the old server and the error in the title started to appear and I can't start the Microsoft Exchange Address Book service. It doesn't seem to affect the users who are on Outlook 2003, 2007 and 2010. How do I locate that duplicate endpoint and kill it?