If you are wondering why your insert key no longer toggles between insert and overtype mode, it is because you have upgraded your version of Microsoft Office. Microsoft felt that the INSERT key should no longer toggle between insert and overtype. There is no longer an easy way to switch into overtype mode, however, Microsoft did create an option to set the INSERT mode back to the way it worked in Word 2003 and earlier versions.  Instruction can be found on Microsoft’s website at: http://support.microsoft.com/kb/982946.