This post discuss how to remove and reinstall Microsoft Forefront Security for Exchange Server in Essential Business Server.
Important these steps will remove FSE, after you follow these steps, FSE will be removed from your server. Any settings that you have made will still remain in the configuration file in the Microsoft Forefront Security folder. The incidents database file, Statistics.xml file, and your licensing information will also remain. Before uninstalling, we recommend that you backup up Microsoft Forefront Security for Exchange. For more information about how to back up and restore Forefront Security for Exchange, click the following link:
Backing up and restoring Forefront Security for Exchange Server http://technet.microsoft.com/en-us/library/cc765430.aspx