You can connect your computer to a projector to give a presentation on a large screen.First make sure the projector is turned on, and then plug the display cable from the projector into a video port on your computer.
Then press Win+P or run DisplaySwitch.exe and choose your preferred display.
Note:1.You can use this same procedure to connect your computer to a monitor
2.This will have no effect if you’ve only one display connected
I need to know HOW to get a part of the picture in the computer to display on the screen, not just the whole screen. This does not answer the question.