Just use the tiny Never10 app linked on those instructions. It sets the same registry keys that the group policy editor sets if you follow Microsoft's instructions for their corporate customers for preventing the upgrade.

https://www.grc.com/never10.htm

(and yes, I know it is from Steve Gibson, who can be a terrible hack, but this is one of his good pieces of work)
_________________________
Remind me to change my signature to something more interesting someday