If you have uninstalled Office 2007 from you system and rolled back to Office 2003, you may have the following error message when you try to configure a user account:

There was an error locating one of the items needed to complete this operation. It might have been deleted.

To fix it, go to the following location:

C: ->Program Files ->Common Files ->System ->MSMAPI ->1033

then delete the file "mapisvc.inf" and remove the profile in Outlook, then recreat the profile.

The mapisvc.inf was created by Office 2007 and was removed by uninstalling.