The problem could be with loosely connected hardware, the display adapter driver, or a recent Windows Update which messed up the settings. Your PC can’t project to another screen ...

Are you unable to project to the PC because the Projecting to this PC option is greyed out or disabled in Windows? Then follow this post to fix the issue.

The Anniversary Update includes a new feature that lets you use Wi-Fi to project the display from a Windows 10 phone or computer to your Windows 10 PC. Here's how to set it up.