Sure, if "computer" to you means "laptop or desktop PC".
My smartphone is a computer, which I use at home and work, and it sure as hell doesn't run Windows. Smartphones are a far more significant type of computer in the modern world than laptop or desktop PCs.
AWS instances run Windows too. And MS makes money off those instances. Also, Azure runs Linux too. Microsoft is in the post-Windows phase and it's working on things that will keep it relevant long term