Your PC can only be projected to from devices on the same wireless private and domain networks, but not on public networks. You must be signed in as an administrator to install or uninstall the Wireless Display optional feature. This tutorial will show you how to install or uninstall the Wireless Display optional feature in Windows 10 for projecting to this PC by devices with Miracast Connect app. Starting with Windows 10 version 2004, the Connect app for wireless projection using Miracast is no longer installed by default, but is available as an optional feature. See also: Get Wireless Display app for Xbox One in Microsoft Store

The Projecting to this PC feature uses the Connect app to allow you to wirelessly project your Windows Phone, another PC, or Android devices to the screen of this PC, and use its keyboard, mouse, and other devices too. The Wireless Display optional feature adds the Connect app in Windows 10 allowing other devices on the same wireless network to use Connect to wireless display to wirelessly project to your computer with Miracast supported hardware. You can use this to share what you’re doing on your PC, present a slide show, or even play your favorite game on a larger screen.

Miracast is a wireless technology your PC, laptop, or tablet can use to project your screen to wireless TVs, projectors, and streaming media players that also support Miracast. How to Install or Uninstall Miracast Connect Wireless Display Feature to Project to this PC in Windows 10

Miracast windows 10 qnet