Airmypc Free [verified] Site

If you strictly need a free solution, the landscape is trickier for Windows-to-AppleTV mirroring, but here are the closest reliable options:

Unique to AirMyPC is the ability to stream your webcam and microphone to your TV, essentially turning your large screen into a video conferencing hub.

: You can choose to mirror only your screen, only your audio, or both simultaneously. Webcam Streaming