Hi,
You're right, many Anti-virus programs like Avast, Norton, Kaspersky, etc. include features that show which applications are currently accessing your webcam. But you may also use the Windows Task Manager or a third-party software like Process Explorer to get this information if you want multiple ways to check this.
**Windows Task Manager**:
1. Open Task Manager by pressing `Ctrl + Shift + Esc`.
2. Click on `More Details` to expand the Task manager.
3. Go to the `Performance` tab and select `Webcam` in the sidebar. This will display all the applications that are currently using your webcam.
**Process Explorer**:
1. Download and install the **Process Explorer** tool from the Microsoft website.
2. Run Process Explorer as an administrator.
3. Go to `Find > Find Handle or DLL`.
4. In the `Handle or DLL substring:` box, type in `WindowsCamera.exe` or `FrameServer.dll`, and click on 'Search'. This will pull up a list of processes that are currently using these files.
As for your other query regarding the registry path, there isn't a direct registry key which shows which application is currently using the WindowsCamera.exe or FrameServer.dll. But, you can use the steps above to find that information.
Remember to use these tools carefully, as they provide detailed information about your system’s processes and changing something mistakenly can cause serious issues with your system.
I hope this helps! Let me know if you have any other questions.