Hi,
To make sure the camera issue is only with Zoom or general, type “Camera” in your search bar and press Enter. Does it work there?
Is this a laptop or a desktop?
Press Windows + R, then type MSINFO32 and hit ok.
Take a screenshot of that window and attach it to your next reply.
Some laptops have a physical switch to enable the camera:
Method 1: Locate a button on your keyboard featuring a camera symbol, typically on the F1-F12 keys.
Similar to this:
https://th.bing.com/th/id/OIP.JDIWtfGA4gfWgwhPERI9ZAHaE5?pid=ImgDet&rs=1
Press that key or Fn + the camera logo key to enable the camera and then you can use it again.
Method 2: Please check the camera lens carefully to see if there’s a cover, such as a camera shutter. Slide it to uncover the webcam.