From Bust A Tech:
WebcamViewer is a very simple click-and-run application to enable you to have a view on your webcam. The Interface is simple, the first thing you have to do is to choose your Webcam.
At the top left of the interface, choose the appropriate webcam. Please take note that some user might experience having Google Camera Adapter under the list, which is not the real webcam, choose the correct one.