How to change "My Office" launch OneNote instead of OneNote 2016?
In general, "My Office" launch OneNote for Windows 10 (OneNote UWP) in default.
But, you can change to launch OneNote 2016.
Change onenote: protocol to make "My Office" launch OneNote 2016.
Steps:
1) Open Windows 10 Settings -> Apps -> Default apps -> Choose default apps by protocol.
Find the URL:OneNote Protocol, in "[+] Choose a default", select "OneNote 2016" from "Choose an app" list.
Click "My Office" -> Programs -> OneNote -> Open, it will launch OneNote 2016.