UseRegionalCharset registry value is disabled or missing on Exchange Server 2003

[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: 2005-12-15

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine the language settings that are used by Microsoft Outlook® Web Access clients:


The UseRegionalCharset registry value causes UTF-8 message bodies to persist in the store in the regional character set or codepage instead of in UTF-8 format.

The Exchange Server Analyzer also queries the Active Directory® directory service to determine the value of the serialNumber attribute for all objects that have an object class of msExchExchangeServer. If the string value includes "Version 6.5", the computer is running Exchange Server 2003.

The Exchange Server Analyzer displays a warning message if either of the following conditions is true:

  • The UseRegionalCharset entry for an Exchange 2003 server is not present.

  • The UseRegionalCharset entry has a value of anything other than 1.

This message indicates that the UseRegionalCharset registry parameter on this Exchange 2003 server is disabled or missing. This setting may cause unintended character set encoding for Outlook Web Access messages, where some messages may be unreadable by some clients.

When you use Microsoft Internet Explorer 5 or later versions to access Outlook Web Access, Exchange Server 2003 uses the browser's language settings to determine which character set to use to encode information such as e-mail messages and meeting requests.

If you expect Outlook Web Access users in your organization to send mail frequently to recipients who use a variety of character sets, you can modify registry settings so that users who are running Internet Explorer 5 or later versions can use UTF-8 encoded UNICODE characters to send mail.


This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.

To restore the default language setting for Outlook Web Access

  1. On the Exchange computer, open a registry editor such as Regedit.exe or RegEdt32.exe.

  2. Navigate to: HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeWEB\OWA\

  3. If UseRegionalCharset does not exist, follow these steps to create it:

    1. On the Edit menu, click New, and then click DWORD Value.

    2. Type UseRegionalCharset for the name of the DWORD, and then press Enter.

  4. If UseRegionalCharset exists, double-click it to modify it.

  5. In the Value data box, type 1, and then click OK.

  6. Close the registry editor.

Before you edit the registry, and for information about how to edit the registry, see Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows registry" (

For more information about Outlook Web Access language settings, see the "Exchange Server Client Access Guide" (