And the only thing he use it for entertainment is browser (for reading novels)
If I am managed to setup all these properly on other system. I doubt him would ever notice a difference.
Non tech user just can't care about what system he is using less. All matter for him are tools that help him to finish his work.
What about dvd/cd or install some new softwares? Well, I am the in house tech support.
That was a majority use-case between 2005-2015. Now it's a niche case (yeah, even if absolute numbers are still big enough, relatively speaking it's a niche)