In this post, I discuss ways to try to do it. There are various ones. Removing the numberpad driver (NOT the touchpad's driver) from Windows Device Manager seemed at first the best way, but it proved to be temporary. Others later proposed various ways to try to remove it permanently, but those don't seem to work, either.
TLDR; See below for how to do that if you may prefer to cut to the chase, but interested readers may want to understand a few things first, like what I mean by the Numberpad feature, and the problem that may prompt folks to seek how to disable it, as well as other solutions that I found had been proposed (even before I wrote this post) but also did not work. Then I conclude with what has, for me (so far).