Microsoft intellimouse optical. I recently reformatted, and prior to that, I had my left and right side mouse buttons assigned to my Q and E keys on the keyboard. I must have had an older driver because the current microsoft driver (5.0) only seems to give you a drop down menu with various functions, but no option to assign a particular key. I've tried a search on microsoft with no luck. Am I missing something obvious, or is there anywhere I can download older drivers for an intellimouse? Thanks in advance.