You receive the "A recently installed program may cause Microsoft Office or other e-mail-enabled programs to function improperly" error message when you start Outlook

The Microsoft Windows Messaging Subsystem (WMS) installs the MAPI core files in the C:\Windows\System32 folder. Versions of Outlook that are earlier than Microsoft Office Outlook 2003 access the MAPI core files from that location. In Outlook 2003 and in later versions of Outlook, the key MAPI core files are stored in a common location.

Simple MAPI programs, such as Microsoft Outlook Express, Qualcomm Eudora, Netscape, and other third-party programs, install and access the Mapi32.dll file from the following location:You can click Send To on the
File menu to send documents in the programs that support simple MAPI programs.

Note This problem may affect the Microsoft Exchange System Manager, even if the Microsoft Exchange server is not on the same computer as the Exchange System Manager. The Exchange System Manager does not work if you select to replace the MAPI core files with the Outlook MAPI files after you run the Fixmapi.exe utility. Additionally, if you select not to replace the MAPI core files with the Outlook MAPI files, Outlook may not work as expected. You will receive the error message that is listed in the "Symptoms" section of this article each time that you start Outlook until you replace the MAPI core files with the Outlook MAPI files.

We recommend that you do not have Microsoft Outlook 2002 or an earlier version of Outlook on the same computer as the Exchange System Manager or the Exchange server. If you are using Outlook 2002 or an earlier version of Outlook, use Microsoft Outlook Web Access or a Terminal Server session to access e-mail messages to avoid this problem.