Cortana is PITA!! I have configured my mouse controls to open Start menu by clicking on control #4. Lately when I click for the start menu, cortana pops up when I don't want it. I have updated my mouse settings, but still don't always get the Start Menu, but Cortana. I almost never use Cortana. but want it to be available on my control.
The upgrade I added to my MX Revolution mouse added some features that were unnecessary and changed the way my mouse worked. Deleted the upgrade and went back to the previous version which works the way I prefer.