MAPI32.DLL error after clean install

I installed Office 2003. Restarted my computer and clicked on the outlook icon, and an error message said;

"Cannot start Microsoft Office Outlook. MAPI32.DLL is corrupt or the wrong version.
This could have been caused by installing messaging software. Please reinstall Outlook."

I reinstalled it a few times and it said the same thing. What's wrong here?

This is a common error which seems to pop-up after you uninstall Outlook 2007 or Outlook 2010 and install Outlook 2003 again. This is often a procedure that you have to do because your new PC shipped with a trial version of Office 2010 while you are still perfectly happy with Office 2003 or simply decide not to upgrade just yet. It’s your pick of course ;-)

Before installing Outlook 2003 again, make sure you first uninstall Outlook 2007/2010 or even the entire Office 2007/2010 suite if you are not going to use it.

  1. Navigate to;
    C:\Program Files\Common Files\System\MSMAPI\<locale ID>
    Replace <locale ID> with the number representing your language. Usually only 1 number is listed there. 1033 represents English.
  2. Here you’ll find the file MSMAPI32.DLL.
    Alternatively you could do a search on this file name to locate the folder.
  3. Rename this file to MSMAPI32.OLD.
    Note that you do not rename MAPI32.DLL itself but MSMAPI32.DLL.
  4. Start Outlook 2003. Windows Installer will start and it should rebuild MSMAPI32.DLL automatically.

If it doesn’t repair itself, you should try running a repair on Outlook 2003 by running setup again from the installation CD.

Note: After a downgrade of Outlook, it is always highly recommended to recreate your mail profile as well.

Cannot start Microsoft Office Outlook. MAPI32.DLL is corrupt or the wrong version. This could have been caused by installing other messaging software. Please reinstall Outlook.
The MAPI32.DLL error is a bit misleading as the actual issue is with MSMAPI32.DLL.