Set Mozilla as the default browser using the Mozilla preferences. Integration with Windows seems to work quite well - clicking a HTML file from explorer or most applications correctly loads Mozilla. However, it does not work correctly when using Outlook as a mail client. Clicking on a link in an outlook message will cause Mozilla to load correctly, but a dialog with "Locate Link Browser" is also displayed. This dialog is asking you to locate a .EXE file. If you cancel this dialog it will be displayed next time you select a link. If you select a .EXE file, then the dialog will not be displayed again. It turns out the problem is a preference inside MS Outlooks part of the registry. Specifically, the registry key: HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Outlook\Preferences Has a subkey named "InternetBrowserPath". Note that this is for Office 2000 - presumably Office XP uses a "10.0" key :( If this key is empty or invalid, the "Locate Link Browser" dialog will be displayed. The EXE you select will be written back to this registry. I think a patch that carefully checks for this key and tries to update it to the mozilla EXE as the same time we set the other registry entries would not be too hard. Should we try and handle this situation?
hrm - it appears this can be treated as a dupe of bug 59078. If the DDE settings described in that bug are removed, then Outlook does seem to work fine, and ignores the "InternetBrowserPath" entry. *** This bug has been marked as a duplicate of 59078 ***