You receive an "A required component is missing" error message when you try to start Outlook 2000 (197034)


The information in this article applies to:

  • Microsoft Outlook 2000
This article was previously published under Q197034
IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry

SYMPTOMS

On computers running Microsoft Windows 95 or Microsoft Windows 98, you may receive the following error message when you start Microsoft Outlook 2000: 
Cannot start Microsoft Outlook. A required component is missing:
OMI9.DLL. Please install Microsoft Outlook again.
On computers running Microsoft Windows NT 4.0, you may receive the following error message when you start Microsoft Outlook 2000: 
Cannot start Microsoft Outlook. A required component is missing:
OMINT.DLL. Please install Microsoft Outlook again.
You may also receive the following error: 
Unable to open your default e-mail folders. An unexpected error has
occurred. MAPI was unable to load the information service PSTPRX.dll.
Be sure the service is correctly installed and configured.

CAUSE

If the installed version of Outlook conflicts with the MailSupport registry key value, the error message will be generated.

RESOLUTION

To resolve this issue, correct the registry key.

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To check or change the registry key value, follow these steps:
  1. On the Windows Start menu, click Run, and then type regedit.
  2. Navigate to the following registry key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Office\9.0\Outlook\Setup

  3. In the right pane, click MailSupport.
  4. Use the following table to determine which Value data to enter.

    Internet Mail Only = 0 Corporate or Workgroup = 1

    Type the value, and then click OK.
  5. Exit the Registry editor and start Outlook.
Modification Type:MinorLast Reviewed:10/7/2004
Keywords:kberrmsg kbstartprogram kbprb KB197034
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