If the webcam is displayed in Device Manager but doesn’t work, access its Properties, find the Driver tab and click Driver details. You will see the list of drivers used to operate the camera. If one of them is stream.sys, it means that your webcam driver was released a very long time ago and it just can’t work in many new apps. If your computer is a laptop, check its function keys. Some models feature a dedicated key to disable the camera. Try turning the camera on by pressing such key.