UseAltRegionalCharset and UseRegionalCharset registry values are both enabled

[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 entries to determine the language settings that are used by Microsoft Outlook® Web Access clients:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeWeb\OWA\UseRegionalCharset

    A setting of 1 causes UTF-8 message bodies to persist in the store in the regional character set or codepage instead of in UTF-8 format. This is the default setting for the Exchange Server 2003 UseRegionalCharset registry value.

  • HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeWeb\OWA\UseAltRegionalCharset

The level of the browser determines message encoding if the following conditions are true:

  • The UseAltRegionalCharset key is not set or is set to 0.

  • The related UseRegionalCharset is similarly not set or is set to 0.

An uplevel browser, Internet Explorer 5 or a later version, sends messages in UTF-8. An earlier browser, or one other than Internet Explorer 5, sends messages in the appropriate encoding for that browser's acceptance language.

The UseAltRegionalCharset key only changes the behavior for browsers configured for the languages in the following list:

  • Korean : KS_C_5601-1987

  • Japanese: shift_jis

  • Western Europe: windows-1252

  • Russian: windows-1251

  • Central Europe: windows-1250

If the UseAltRegionalCharset key is set to 1, both uplevel and earlier browsers send messages in the following encodings:

  • Korean : euc_kr

  • Japanese: iso-2022-jp (JIS)

  • Western Europe: iso-8859-1

  • Russian: koi8-r

  • Central Europe: iso-8859-2

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 6.0", the computer is running Exchange 2000 Server.

  • If the string value includes "Version 6.5", the computer is running Exchange Server 2003.

The Exchange Server Analyzer displays a warning if the following conditions are true:

  • The UseAltRegionalCharset and the UseRegionalCharset are both present

  • The UseAltRegionalCharset and the UseRegionalCharset are both configured to use a value of 1 on an Exchange 2000 server or an Exchange 2003 server.

For Exchange 2000 Server and Exchange Server 2003, the alternative character sets take precedence when the following conditions are true:

  • The use of regional characters is turned on – the UseRegionalCharset registry key REG_DWORD value is set to -1.

  • The use of alternative character sets is turned on – the UseAltRegionalCharset registry key REG_DWORD value is set to 0x1.

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

  2. Determine which Outlook Web Access language settings are appropriate for the Exchange Server environment and remove the key that is not appropriate.

    1. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeWEB\OWA\

    2. Select the key to be removed, right-click the key, and then select Delete from the drop down list.

  3. 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 following Exchange Server resources:

The "Exchange Server Client Access Guide" (

Microsoft Knowledge Base article 311342, "XCCC: Exchange 2000 Server SP2 Server-Side OWA Registry Keys" (