OFF97: Removing MS Exchange Breaks MS Outlook (156819)


The information in this article applies to:

  • Microsoft Office 97 for Windows
  • Microsoft Outlook 97
  • Microsoft Exchange Client 4.0
  • Microsoft Exchange Windows NT client 4.0
This article was previously published under Q156819

SYMPTOMS

You may receive the following error message when you try to start Microsoft Outlook 97:
A required .DLL file, MAPI32.DLL, was not found.

CAUSE

This will occur if both of the following are true:
  • Microsoft Exchange 4.x was installed on your computer.

    -and-

  • You removed it (by clicking Remove All in the Microsoft Exchange Setup program) after you installed Microsoft Outlook 97.

RESOLUTION

If this occurs, you should reinstall Microsoft Outlook 97. Use the following steps to do this:
  1. On the Start menu, point to Settings, and click Control Panel.
  2. In the Control Panel, double-click Add/Remove Programs.
  3. In the list of installed applications, click either "Microsoft Office 97, Professional Edition" or "Microsoft Outlook 97", whichever is available. Click Add/Remove.

    The Setup program starts and after a brief period of time you should see a dialog box containing up to four buttons: Add/Remove (not visible for "Run from Server" installations of Office), Reinstall, Remove All, and (in some cases) Online Registration.
  4. Click Reinstall.

    The reinstallation process copies all required files onto your hard disk. When Setup is complete, restart Windows if you are prompted do so.
Microsoft Outlook 97 should now start properly.

STATUS

This behavior is by design of the Microsoft Exchange 4.x Setup program.

MORE INFORMATION

The file Mapi32.dll, normally stored in the \Windows\System folder, is used by both Microsoft Exchange 4.x and Microsoft Outlook 97. However, the file is treated differently by the two different programs:
  • Microsoft Outlook 97 treats Mapi32.dll as a shared component. That is, the Microsoft Outlook Setup program (as a separate program or as part of the Microsoft Office 97 Setup program) does not remove Mapi32.dll from your system unless it is sure that no other program is using the file.

  • Microsoft Exchange 4.x, on the other hand, does not treat Mapi32.dll as a shared component. So, if you use the Setup program to remove Microsoft Exchange 4.x from your computer, Mapi32.dll is removed, even if you click "Remove None" when prompted by the Setup program whether you want to remove shared components.
When you remove Microsoft Exchange 4.x, you also remove the Mapi32.dll file, which prevents Microsoft Outlook 97 from starting properly. If this occurs, you must reinstall Microsoft Outlook 97 to correct the problem.
Modification Type:MinorLast Reviewed:8/17/2005
Keywords:kbprb KB156819
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