I think I convinced my brother to help him install Ubuntu since he is having problems with Windows activation, I hope he doesn't get cold feet, he is not so tech savvy and he thinks that he needs some extra knowledge for Linux. He will need some Linux distro soon because he will have projects on his faculty which require it, better to start learning sooner than later.
@Vortax
I feel you, you can't convince them to use Signal and even harder to use different OS which is for non techie same as Windows, they only use it for web browsing. What is your brother doing mostly on his computer? If its web browsing then Mint or Ubuntu are great for him. You can try to sell it as "non-malware" OS, and faster experience overall. If he is gaming then there is nothing you can do to persuade him, you will make him even hate Linux.
@Vortax
True
@nikolal
Well, gaming in Linux is nowadays much better than before... But it still sucks. For much that I love Linux, when I game I boot to a windows partition.