You can refresh the screens in the existing Window Layout by selecting "Current Computer" from the drop-down in the Regions panel, the one that says "<Pre-defined Computer>". The monitors attached to your PC are stored with the layout at the time of creation (hence "pre-defined", they were defined at that point -- it will go back to saying pre-defined computer after you save it), so that anyone else can load your configuration and see it exactly as it appears on your PC.