Updated Outlook XP - get "Not implemented." for new item

I just upgraded Office 2000 using a copy of Office XP on CD, then let the MS
Office Update site install all available updates in two passes. I am now able
to run Outlook, except I get an error message "Not implemented" whenever I
try to create a new contact, appointment, task, etc. For any item other than
a contact it gives the message box when I click New. For a contact (which
uses a custom form) it gives the error when I click Save and Close.

Note that the update service may have downloaded some Office 2003 updates,
as there was also an icon for Outlook 2003, but it runs the installer and
asks for a key that I don't have.