Solution Steps

1. Check camera privacy settings: Settings → Privacy → Camera → Allow apps to access.
2. Close other apps using camera (only one app can use camera at a time).
3. Test camera in different app (Camera app, different video call app).
4. Update camera drivers: Device Manager → Imaging devices → Update driver.
5. Restart computer.
6. Check physical camera cover or lens obstruction.
7. Unplug and replug USB webcam if external.
8. Grant camera permissions to specific apps in privacy settings.