There was some update for Win 7/Win 8 that would set you up for the Win 10 upgrade.. I have 2 laptops that I've upgraded to 10 from 7 and I'm liking it so far...
You can't do much about the 'security' automatic updates.. They are doing that so you don't leave a hole in the OS that can be exploited easily.. My Dad is 72 years old, very smart person, and has no clue on computers.. Been hit with most, if not all of the "stupid user" scams they have... Ugh..
I like the iPad idea... That's really all he needs too...
To change your Win 10 updates to an extent (you still can't control the security updates), you can do a 'search' for "windows update". Click on the "Windows Update Services" link. Go to Advanced Update Settings. Check the "Defer Updates" option. Go to the "Privacy Settings" and turn everything you can find to "OFF". You have to click thru all the menu items on the left side of the screen.
I hate MS as much as anyone, but what else are you going to do?? Oh, go to Apple... Well, that's always an option, so if that works for you, great... Not so much for me..
Good luck!
Mitch