Ensure your laptop is selected from the touch screen or push button controller, and adapter/cable connections are secure (HDMI or VGA).
- Choose Apple menu > System Preferences, click Displays, then click Display. Open the Display pane for me.
- Click Arrangement, then select Mirror Displays to DUPLICATE laptop and projector output. Or de-select Mirror Displays to extend displays (two outputs for laptop and projector).
- Adjust resolutions as needed for best quality output.
Shortcut key to accomplish this: Command + F1