I have Office 2003 pro. This problem only started today: every time I open Outlook, the Windows installer open an Office 2003 pro installation 3 times.
This repeats again every time I create a new mail.
I found that if I remove the tick from "Use MS Word as HTML Editor" this does not happen.
I tried Detect and repair, uninstall and re-install, applying updates, using the uninstaller tool. All these did not work.