to restore outlook to factory default settings:

regedit, and delete:
HKCU\Software\Microsoft\Office\11.0\Outlook
HKCU\Software\Microsoft\Office\8.0\Outlook
HKCU\Software\Microsoft\Office\Outlook
(and anything else called Outlook)

Delete:
C:\Documents and Settings\user\Application Data\Microsoft\Outlook
C:\Documents and Settings\user\Local Settings\Application Data\Microsoft\Outlook