DeviceOK
SearchDevice checks
Home / Errors / Windows camera / 0xA00F4243
Windows camera error

0xA00F4243 Camera in use by another app

Microsoft maps 0xA00F4243 (and related variants it documents) to another app or process using the camera. The camera may be healthy but unavailable to the app you are opening.

Test the camera firstDiagnose camera problem
First action

Verify detection before changing more settings

Close other camera-using apps, then run DeviceOK's webcam test. A successful browser test after closing them is strong evidence against a completely dead camera.

Safe sequence

What to check next

  1. 1

    Quit meeting, streaming and camera utilities that may keep the camera open.

  2. 2

    Check Windows Privacy & security > Camera permissions for the affected app.

  3. 3

    Restart Windows if you cannot identify the process holding the camera.

  4. 4

    If DeviceOK works but one app still fails, troubleshoot that app's selected camera and permissions.

Retest

Know whether the change worked

After each meaningful change, run the DeviceOK webcam test again. If DeviceOK receives video but one application still fails, move to that application's camera selection and permission path.

Retest webcam