Some classrooms are setup with 2 displays and 2 projectors. The classrooms with touch panels will have a "Screen Selection" button to change what displays on the projector. The older smart classrooms do not have this option and must be configured through Windows as follows:
Right click anywhere on the desktop and choose "Screen Resolution"
From the "Multiple Displays" menu choose the option that is right for you.
"Duplicate Displays" will allow you to show the same image on each screen and each projector.
"Extend these Displays" will treat the monitors and projectors as two separate screens.