You may not be aware (as evidenced by the number of hardware devices I see being sold that do the same thing), Windows 10 has the ability to mirror your screen to any other Windows 10 computer, as well as other devices compatible with the Miracast standard. It’s a easy, free way to add an additional monitor to your desktop, or even send your whatever is on your screen to a television.
Let’s use my situation as an example.
My computer at home is an all-in-one, with one large monitor. That works fine most of the time, but if I am going to do some writing, a second monitor is essential so that I can have one screen for my research, and a second for my word processor. Right there in my bag is a Windows Surface Pro, just waiting to be used.
To set it up as a second monitor (you only have to do this once), you go to the lower right-hand corner of the display, where there is a box that looks like a dialog bubble from a cartoon. (Windows calls it the “action center.”) Click on that, and you’ll see a number of buttons, one of which is labeled “connect.” You’ll then see a link that says, “Projecting to the PC.” Follow the prompts. If you don’t want to have to give permission every time, select “every time.”
Now go to the computer from which you want to project, select the action center, then “connect,” and then select your laptop from the list of devices that appears. You are given the option to “allow input from a keyboard or mouse connected to this display,” meaning that you’d be able to use both the keyboard on your desktop and laptop, but I suggest leaving this unselected unless you have some need for such functionality. I find it makes the connection a little wonky.
Then you get to decide what you want projected. You can mirror your screen, perhaps if you want to show a client something on your laptop without having him or her looking over your shoulder, or you can “extend” the screen, making it a second display.
In my home office, I have a television across the room. Without even knowing it could do such a thing, when I hit the connect button on desktop, one of the options it offered was the television. Now, for example, if I’m learning a new program and want to be able to follow along with a YouTube video, I just throw it over to the television so that I don’t have to swap back and forth.
And speaking of instructional videos, here is one I found on YouTube to walk you through the process of setting up the second display. Enjoy.