This may be a Windows 10 or Outlook 2007 problem! After recent W10 updates my Outlook 2007 instant search always returns 'nothing found'. After a bit of research I've rebuilt the index but to no avail. If I start Outlook 2007 in safe mode all is fine and the search works perfectly. I have removed all the com addins except for AVG (which is still installed when running in safe mode) but when restarting normally the search fails to work, returning 'nothing found'. Any ideas?