Možných řešení je na netu milion, zkus např.

Right click on windows icon on the left corner of the taskbar. Click on the settings icon (just above the power icon), this will open windows settings panel. Click on the privacy icon (lock symbol), to open the privacy panel. Click on the camera icon, to open the camera privacy settings panel. select on or off for each application. To use camera with Skype: switch it on for Skype. Now the camera works with Skype.

https://superuser.com/questions/1210962/your-webcam-is-currently-being-used-by-another-application