Not all IR cameras are the same. The driver abstracts the hardware differences, allowing Microsoft’s Windows Hello framework to work consistently whether you are using an HP EliteBook, a Surface Pro, or an external Logitech Brio 4K.
If you are dealing with a missing or "unavailable" Windows Hello Face software driver windows hello face software driver
A poorly written face driver will drain your battery. An optimized driver puts the IR sensor into a low-power "idle" state when not in use and wakes it instantly upon a user presence signal (e.g., opening the lid). Not all IR cameras are the same