In this guide, we will show you how to do this if you want to expand your desktop display and use your laptop as a second or third display for your PC. Although this may seem like a simple process, all you have to do is connect your laptop to the desktop with an HDMI cable (or other video input cable), the fact is that it doesn't work that way. The HDMI port (or VGA, DVI, or DisplayPort) on the laptop can only be used to output its display, not as a video input to other devices. This means that if you want to display the laptop screen on a larger monitor (TV, monitor, projector, etc.), or connect it to another monitor to expand the display of the laptop, you just need to connect the additional monitor to the laptop. However, you cannot use a cable to connect the laptop to the PC so that the laptop displays what the PC is outputting. Therefore, in order for the monitor of your laptop to be used as the monitor of another device, you must use the built-in features on Windows or use third-party software to make these two devices work correctly. In this guide, we will show you the different options for setting up your laptop as the second or primary display of your PC.
A better choice is to use third-party programs, such as Space Desk, without being limited by some compatibility issues that plague Miracast. To use Space Desk, you only need to download the Space Desk Drive program on the main system and the Space Desk Viewer program on the laptop to use it as an extended display on the main system. You can watch this video from the YouTube channel Pearl Crew to learn how to set up Space Desk, instead of giving you a step-by-step list: With Space Desk, I can make my laptop work as an extended display, which is much faster and easier than trying to use Miracast.