Microsoft has broken Windows Hello facial recognition — it no longer works in the dark

Windows Hello has seen a minor downgrade this week, as the service now requires the use of a color camera in tandem with IR sensors to sign users in. While the update was announced back in April, users are only now seeing the fruits of the update, with Windows Hello no longer functioning in the dark.

Facial recognition through Windows Hello has used IR sensors to save a 3D scan of a user's face, without the need for visual confirmation through a webcam, for years. This allowed users to sign in with Windows Hello Face recognition in the dark, just as Apple's Face ID sign-in works. But the new change, made in response to a "spoofing vulnerability" found in April, makes the login service both more secure and more inconvenient.

The change has seen varying responses in reporting so far. Some reports from Windows Central and elsewhere online confirm the Windows Hello login no longer functions in the dark, whereas PCWorld reports the reflection of light coming from a laptop screen was enough to give the webcam something to work with.

There is some heightened concern for those users with darker skin tones. Darker faces can be harder for cameras to resolve in low light, perhaps making Hello's functionality in the dark even worse for people of color. Just as motion-activated faucets and other tools can fail to see non-white hands in some situations, Windows Hello may prove worse in the dark for those whose faces reflect less light.

There does exist a workaround to bypass the new webcam requirements for Windows Hello. Users can use Windows Device Manager to disable their color webcam, at which point Windows Hello will still function using only the IR sensors.

Of course, disabling your webcam means that you will no longer have a working camera, so the usefulness of this workaround exchanges the problem of "no Windows Hello in the dark" for "no camera in meetings", a swap few people would be willing to make.

And of course, quick Windows Hello sign-in is possible in many ways beyond webcam facial recognition. PIN, password, and fingerprint login options all already exist for PC users without built-in Windows Hello-compatible webcam/sensor solutions, and those worried about not being able to log in in the dark would be best served by swapping their login option to another, more accessible mode.