Microsoft’s Windows Hello face unlocking feature no longer works when the room is dark. This is not a bug. Microsoft quietly changed Windows Hello in April to fix a vulnerability in Windows Hello spoofing. Windows Hello has lost some key features in Windows 11 after Microsoft fixed the security flaw. Windows Central noticed the April change after some Surface Laptop owners have noticed that they can no longer sign in with their face in a darkened room. Microsoft states in its April Windows Update Patch Notes that Windows Hello facial recognition will only work if a visible face is seen by the color camera. This is for enhanced security.

If you disable your webcam from the Windows 11 Device Manager you can make Windows Hello work in a darkened room. However, you will not be able to use your camera for any apps or video calling. It’s possible to disable the webcam in the Windows 11 Device Manager and still have Windows Hello work in a dark room. However, you will not be able to use your camera for video calls or apps that require it.

Microsoft combines the color camera with IR sensors to detect a person’s face for its Windows Hello service. Microsoft rated the security vulnerabilitydiscovered by Nanyang Technological University as “important”. It has not been publicly disclosed nor exploited. Microsoft says it’s “less probable” that malicious actors would exploit this locally.

Microsoft has been contacted to see if it can get Windows Hello to work in the dark in the future. We will update you accordingly.