Microsoft KB Archive/192119

= PRB: MAPI/CDO (1.x) Applications Fail After Outlook Express 4 Install =

Article ID: 192119

Article Last Modified on 2/12/2007

-

APPLIES TO


 * Microsoft Messaging Application Programming Interface
 * Microsoft Collaboration Data Objects 1.0a
 * Microsoft Collaboration Data Objects 1.1
 * Microsoft Collaboration Data Objects 1.2
 * Microsoft Collaboration Data Objects 1.21
 * Microsoft Outlook Express 4.0
 * Microsoft Outlook Express 4.01
 * Microsoft Outlook Express 5.0
 * Microsoft Outlook Express 5.01
 * Microsoft Outlook Express 5.5
 * Microsoft Outlook Express 4.0
 * Microsoft Outlook Express 4.01
 * Microsoft Outlook Express 5.0
 * Microsoft Outlook Express 5.01 Service Pack 2
 * Microsoft Outlook Express 5.5
 * Microsoft Outlook Express 6.0

-



This article was previously published under Q192119



SYMPTOMS
Some customers may encounter challenges with their Extended Messaging Application Programming Interface (MAPI) and/or Collaboration Data Object (1.x) based applications no longer functioning after installing Outlook Express 4.X.



CAUSE
During setup, if the option to make Outlook Express 4.X your default e-mail application is selected, Outlook Express 4.X renames the existing Mapi32.dll on the system to Mapi32.oe, then installs and register its own MAPI DLLs to replace the previous MAPI subsystem.

The MAPI DLLs installed by Outlook Express 4.X include only Simple MAPI, not both Simple and Extended MAPI like the Mapi32.dll installed by Exchange Server, Exchange Client, Windows Messaging, and the full Outlook Client.



RESOLUTION
To restore the full MAPI subsystem, clear the "Make Outlook Express my default Simple MAPI client" check box by following these steps:
 * 1) In Outlook Express 4.X, from the Tools menu, choose Options.
 * 2) Click the General tab, and clear the "Make Outlook Express my default Simple MAPI client" check box.
 * 3) Click OK, and then click OK again.
 * 4) Restart your system.



STATUS
This behavior is by design.

