Re: ,So there's an online fix for not being able to get online?
"I've been supporting my elderly father with his windows 10 machine"
"with his windows 10 machine"
What did you expect? Windows 10 to not Auto Update?
This is like you wanted a can of worms, but you also wanted the worms to stay in the can when opened.
Seriously, unless you want this to happen again and again, you really should change some settings or use another OS (windows 7/8, linux, macOS, windows 10 enterprise).