There is a discrepancy with the Exchange server name between the registry and Active Directory

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2006-12-03

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to determine the value stored in Active Directory for the name of the Exchange server (CN=<ExchangeServerName>). After retrieving this name, the Exchange Server Analyzer counts the number of characters in the name.

The Exchange Server Analyzer also reads the following registry entry to determine the value stored in the Exchange Server computer's registry for the host name of the Exchange server:


Additionally, the Exchange Server Analyzer also queries the Win32_Service Microsoft Windows® Management Instrumentation (WMI) class to determine the value of the Started key for ClusSvc, the Cluster service.

If the Exchange Server Analyzer determines that the following criteria are all true, an error is displayed:

  • The value for CN=<ExchangeServerName> does not match the value for Hostname.

  • The Exchange server name is 15 characters or less.

  • The Exchange server is not running in a Windows cluster.

The most common cause of this error is that the name of the Exchange server has been changed. Changing the name this way changes the name in the computer registry, and it changes the name for the computer account in Active Directory, but it does not change the many references to the Exchange server name that are found throughout Exchange attributes and objects in Active Directory.


Some third-party software will also change the computer name to provide clustering functionality. If you are using such software, you may have to ignore this issue.

Renaming an Exchange Server computer is not supported and is known to cause problems, such as a failure to start the Microsoft Exchange System Attendant service after the computer name has been changed. If the renamed Exchange Server computer does not appear to be functioning correctly in all respects, you can manually remove Exchange Server from the computer using the manual removal process outlined in this article. If the renamed Exchange Server computer does appear to be functioning correctly in all respects, you should rebuild the Exchange server using the rebuild procedure below because this is an unsupported configuration and may cause problems in the future.

To correct this error by performing a manual removal of Exchange Server

  1. Stop all Exchange Server services and completely back up the computer.

  2. Depending on which version of Exchange Server you are running, see the following Microsoft Knowledge Base article:

  3. If you are running Exchange 2000 Server or Exchange Server 2003 and this is the only Exchange server in your organization, follow the procedure outlined in the Knowledge Base article 273478, "How to completely remove Exchange 2000 or Exchange 2003 from Active Directory" (

To correct this error by rebuilding the Exchange Server computer

  1. Move mailboxes, public folders, connectors, and roles to another Exchange Server computer in the organization.

  2. Uninstall Exchange Server from the computer.

  3. To clean up the registry on a computer running Exchange Server 2003 or Exchange Server 2000, follow the registry cleaning sections of the procedures outlined in the following Microsoft Knowledge Base articles:

    Alternatively, you can rebuild the operating system.

  4. Install Exchange Server on the computer.

  5. Move mailboxes, public folders, connectors, and roles to the newly built Exchange Server computer.

For more information about how to deploy Exchange Server 2003 on clusters, see the Microsoft Knowledge Base article 810986, "Microsoft support policy for Exchange Server installations that are running with a third-party Cluster service" (