Exiting the Emulation
If you are running Amiga Forever for Windows and are "trapped" in an Amiga emulation session you can hold down the Escape key for one full second to exit fullscreen mode, or to uncapture the mouse. Then use the Amiga Forever player controls to terminate the running instance.
On advanced configurations with mouse integration enabled this is usually not required, as the mouse can smoothly move in and out of the emulation window.
The Workbench Quit Command
The Amiga Workbench Quit menu item by itself is not needed to terminate the emulation.
The Amiga Workbench screen by itself is a graphical front-end which gives you access to disks and files, and where system tools and other applications can open windows. This is the Amiga equivalent of the Windows Desktop. Programs like Directory Opus can completely replace the Amiga Workbench.
Normally, if you close the Workbench, and unless you have a Workbench replacement or another program running on its own screen, you end up with a blank screen, and no way to use the Amiga operating system. As strange as it may sound, the Amiga Workbench includes a Quit command, which does exactly what it says: it closes the Workbench front-end. This command does normally not shut down the Amiga (or, in the emulation, quit the emulation). As of Amiga Forever 2016, in integrated configurations like Workbench 3.X the system was patched to associate this command to the actual termination of the emulated system.
If you selected the Quit command on purpose (intending to close the Workbench, rather than quitting the emulation) and saw a message like "Cannot Quit yet, there are 3 WB launched program(s)", this usually refers to the programs which were launched at startup ("System/WBStartup" directory) You can press Ctrl+Alt+F1 to open Commodities Exchange and quit these programs.