Try these Windows 10 checks in order:
- Check whether the camera is blocked by hardware
- On many laptops, the webcam can be disabled with a keyboard key that has a camera icon, often used with Fn.
- Also check whether there is a physical privacy shutter or slider covering the camera.
- Make sure Windows camera permissions are enabled
- Go to Start > Settings > Privacy > Camera.
- Turn Camera access on.
- Turn Let apps access your camera on.
- Turn Allow desktop apps to access your camera on, because desktop apps such as Microsoft Teams and browsers need this setting.
- Close anything else that may be using the camera
- Close apps such as video calling apps or browsers that might already be using the webcam.
- Restart the PC and test the camera again.
- Reinstall or refresh the camera device
- Open Device Manager.
- Expand Cameras.
- Right-click the camera and select Uninstall.
- Restart the device so Windows can reinstall it.
- If the camera category is missing, in Device Manager select View > Show hidden devices, then Action > Scan for hardware changes.
- Update the camera driver
- If the camera still does not open, install the latest camera driver for the Dell Latitude 3440 from Dell support for that exact model, then restart Windows.
- If the camera works briefly and then fails again
- This can point to a driver issue.
- In Windows, open Settings and go to the camera settings for the device.
- Open Advanced camera options.
- Enable Basic camera driver mode.
- Restart the app being used and test again.
- Note: this may disable some manufacturer camera features, but it can improve reliability.
If the camera is still missing entirely in Windows after these steps, the accepted guidance in similar Microsoft Q&A cases is that the issue may be hardware-related and should be checked by Dell.
References
- Manage app permissions for a camera in Windows
- Windows camera, microphone, and privacy
- Troubleshoot video camera issues in Microsoft Teams Free
- Camera is not working - Microsoft Q&A
- camera not attached (how to fix???) - Microsoft Q&A
- regarding camera - Microsoft Q&A
- camera not working - Microsoft Q&A