There was an action. It barely went Microsoft's way. You can pull on this reference trail: https://www.zdnet.com/article/we-own-windows-trademark-microsoft/ ht

There was an action. It barely went Microsoft's way. You can pull on this reference trail: https://www.zdnet.com/article/we-own-windows-trademark-microsoft/ https://www.zdnet.com/article/we-own-windows-trademark-micro... I believe the problem is that "Window System" is generic (as in X Window System, often referred to as X-Windows). That made it hard, but not impossible, for Microsoft to defend "Windows." After enough appeals, courts decided "Window" and "Windows" aren't the same thing.