I have a user which has been upgraded to Windows XP SP2. She uses a Dell Optical mouse. She is used to having the mouse inverted (ie you move the mouse forward and the pointer moves down). We believe this option used to be part of either Intellipoint or Mouseware, so we have downloaded and tried both but there is no option to change the orientation. There is a suggested registry fix on the logitech forum, but the key they refer to does not exist!