Windows: Activate your webcam
Steps to Enable Camera Access
Click on Start.
Go to Settings.
Select Privacy.
Click on Camera from the left menu.
Under Allow access to the camera on this device, click on Change.
Make sure Camera access for this device is turned ON.

Find Allow apps to access your camera and make sure it's turned on. This setting allows you to choose if any of your apps can access the camera. It doesn't set which specific apps can access the camera.
NOTE: You can't change camera access settings for individual desktop apps.