Office 2011 for Mac: Reset registration key

1. Remove the following two files:

   rm ~/Library/Preferences/com.microsoft.office.plist
   rm ~/Library/Preferences/Microsoft/Office\ 2011/OLE\ Registration\ Database
   

2. Restart your Mac
3. Open any Office application, it will ask for the registration key.

See also

• Mac OS: backup and restore Microsoft Office 2011