Microsoft makes it impossible to use Windows Hello in the dark.
Since April, it is no longer possible to unlock your laptop using Windows Hello facial recognition in a dark room. What initially seemed like a bug turns out to be a deliberate decision by Microsoft. By resolving a vulnerability in Windows Hello, the feature now only works when the color camera has a view of a face in visible light.
Security over Convenience
The change was implemented via a Windows 11 update. Microsoft states in the patch notes that facial recognition now depends on color cameras and no longer works solely on infrared. This should prevent potential spoofing attacks where Windows Hello was deceived.
No more Infrared
If you still want to log in in the dark, you can disable your webcam in Device Manager. This causes Windows to use only the infrared sensor. But be aware: this also means your camera won’t work in Teams or other apps.
The Verge reports that the vulnerability, which has now been resolved, was discovered by Nyanyang University. Microsoft confirms that the vulnerability has not been exploited and that the risk of misuse is “unlikely”, but still chose a proactive approach.
Whether Microsoft will offer an alternative that works in the dark in the future remains unclear for now.