Replacing windows on my dad's computer with elementaryOS.

Were you getting lots of complaints about how his computer was slow, considering when he bought it?

@bahua he bought it 3 years ago with a bad AMD cpu. It's been slow from the beginning

Does he know it?

I did the same with my grandpa's laptop a few years ago. Turns out the performances didn't change much, and elementary really didn't like the wifi board so I had to make him a script to turn it down and back up on boot or it wouldn't work