Hello, thought I'd make a tutorial about setting up Miracast receiving on Windows 10, so here it is.

First, you will need to open the "Manage optional features" page of the Settings app (Not control panel), you can either do this by searching for the name, or through Settings > System > Optional features.

On this page, you want to press the "Add a feature" button, then write "Wireless Display" in the search box at the top of the popup, select the feature and press Install.

After the feature is installed, try searching for the "Connect" app, if you cannot see it, wait a bit, or log out and back in (If still nothing, reboot), then search for it again.

Click on this app to open it, if it says "<desktop name> is ready for you to connect wirelessly.", you've done it and can now open up your Miracast capable device, like a phone or another computer, and connect to the computer. If you get an error saying your computer is not able to be projected to, first check Wi-Fi (and optionally Bluetooth) is enabled, Miracast sadly doesn't support a wired connection, as far as I know.

By now, you should have a working way to receive Miracast. You may not be able to receive protected content, because copyright sucks, but you can do basically anything else. If you have problems with lag or something, get closer to your access point, with either the computer, other device, or both. You might also have to upgrade the other device's, or your computer's way of receiving Wi-Fi. (unlikely)