Many people want to disable camera in their laptop (may be because of security/privacy concerns). Here is the quick way to achieve this.
Go to Control Panel –> System –> Hardware Tab –> Device Manager.
Under Imaging devices you will find your camera listed (see the image below). Right click on the camera device and click disable option from the context menu.
How to re enable the webcam?
If you wish to re-enable it, follow the same steps and click enable from shortcut menu and it will start working again.