See Microsoft Knowledgebase for information on resetting the various versions of Outlook to their original settings.
The following procedure is untested by Alentus and should be used with caution:
How to restore Outlook
Note: this procedure will reset Outlook to its DEFAULT views and it will NOT restore CUSTOM toolbars or menus.
To restore Outlook views, toolbars, menus or settings, you need to reset the content of the OUTCMD.DAT file.
1. Exit Outlook
2. Locate the OUTCMD.DAT file. If you are running Windows XP and you
installed Outlook on its default path, you can find the file in
"C:\Documents and Settings\-USER-\Application Data\Microsoft\Outlook",
where "-USER-" if the name of your Windows login account. If not, search
your local disk for the filename
3. Rename the OUTCMD.DAT file to a different filename
4. Restart Outlook
5. Once restarted, Outlook should restore the default OUTCMD.DAT file
from scratch and you should be able to use Outlook with its default view