When I upgraded my OS to Windows 10 on my Asus laptop, I lost the ability to turn off my touchpad using fn+f9. I looked online for ways to help solve this issue with no success. Hopefully this will help anyone who is having similar problems.
Step 1: Open the Task Manager
Open your task manager, ctrl+alt+del, or by searching for it.
Step 2: Select Startup Options
Select the startup tab along the top.
Step 3: Disable ETD Control Center
If you don't immediately see ETD Control Center, you can sort the programs by their status.
Disable it by either right clicking or pressing the button at the bottom right-hand corner.