Your computer usually handles this process automatically. If the screen isn’t recognized, there may be a technical issue. Check if both devices are functional, if the cables are properly inserted, and if there’s visible damage on any of them.
If everything is in order, and your computer still doesn’t recognize the second screen, go to the display options. There should be a button to detect new monitors and identify them.
For more detailed information on how to setup dual monitors, feel free to check out our in-depth guide.