Do you run Windows 11 on a laptop and are finding that its built-in camera is not working? If so, its a common problem that can be resolved, mostly.
It can be caused by many reasons, although the top culprits could be a software driver issue, Windows 11 being not up to date, a camera hardware issue and so fourth.
This helpful article should be your first port of call and apply generically to most brands including HP, Lenovo, Dell, Acer etc