How did Windows 3.1’s virtual machine manager get the information to show in the text-mode Alt+Tab switcher?

When I told the life story of the Switch­To­This­Window function, some people were curious about how the virtual machine manager knew about the current windows and their z-order, so that it could show them in the fake text-mode Alt+Tab switcher. The virtual machine manager has a friend, The post How did Windows 3.1’s virtual machine manager get the information to show in the text-mode <KBD>Alt</KBD>+<KBD>Tab</KBD> switcher? appeared first on The Old New Thing....