I made the point a while back that Microsoft’s biggest mistake was missing out on mobile market share. This allowed Android to swoop in and give mobile users a totally non-Windows mobile experience.
All of those mobile users will soon have the option of running Android on their desktops too. They know that they don’t need Windows for their mobile devices, and quite a lot of them now have enough experience computing without Windows to feel comfortable using Android on the desktop too.
It’s just not a Windows-only world any more.