You don't want to display your entire screen. Rather, you only want to show a particular set of MetaTrader4 charts. Consequently, you should select "Display Window" instead, while the particular MT4 platform you want showing is the active window on your desktop.Click on the "Display Capture" option in the popup menu, which will in turn open a "Create/Select Source" box. If creating a new display, simply click on the "OK" button.