When you're in a conference room or class room and need to project, connect your PC using one of the cable connectors in the room, press the Windows logo key  + P, and then choose one of the four options:

  • PC screen only. You'll see everything on your PC. (When you're connected to a wireless projector, this option changes to Disconnect.)

  • Duplicate. You'll see the same things on both screens.

  • Extend. You'll see everything across both screens, and you can drag and move items between the two.

  • Second screen only. You'll see everything on the connected screen. The other screen will be blank.





Reference:

https://support.microsoft.com/en-us/help/27911/windows-10-connect-to-a-projector-or-pc