I've installed Office 2011 and all available updates as of today (January 8/13). Word, Powerpoint, Excel all work fine. However, Outlook won't open. Every time, it opens a dialog box asking me to choose an identity, but whether I choose an existing one or create a new one, the result is always the same: an error box reading, "Could not change to that identity. An unknown error has occurred in Outlook".

I've tried all the suggestions I could find here - deleted the prefs, rebuilt the database, started with the shift key held down. It's the same thing every time. I have no previous installation of Outlook or Outlook Express or Entourage or any Microsoft mail software on this computer. I'm about to chuck it and go back to Apple's software, unless someone has a suggestion that might work. All help appreciated.

David Basskin