If the Wings Engine Desktop has been moved to the wrong monitor you can very quickly move it back to the required monitor:
Hold the Windows key down and press key P several times until the dialog Set as primary display appears on the display on which the Wings Engine Desktop is to be shown.
Once you let go of the keys there will be a query asking whether the display is to be defined as the primary display. Press the Enter key and click Yes following which the desktop appears on the monitor. It may take a few second before the change-over.