Camera or microphone not working in Zoom, Google Meet or Teams

If your camera/mic don't work in a meeting: 1) Check the physical mic-mute key and the webcam privacy shutter/slider. 2) Windows privacy: Settings > Privacy & security > Camera (and Microphone) — turn access ON and enable it for your meeting app (and for your browser, for Google Meet). 3) In the app's own audio/video settings, select the correct camera and microphone and watch the mic level move. 4) Close other apps that might be holding the camera (Zoom, Teams, Camera app) and rejoin. 5) If headphones/an external mic behave differently, or nothing works after this, it may be hardware — see "Audio, speaker, microphone and webcam problems".