Microsoft started seeding first firmware updates for the Surface Pro 4 and Surface Book immediately after the devices went on sale in the US and Canada. Windows Hello, Microsoft's biometric authentication, allows you to use your face, iris or fingerprint to unlock your Windows 10 devices.

This feature was not present in the review units, but Microsoft promised to make it available before the devices hit the stores. With the latest update you can now take advantage of Windows Hello, claims AnandTech.

If you have not set up Windows Hello as yet, go to Settings, choose Accounts and then the Sign-in option. You will need a password and PIN set ready for this. In case you don't have these, you can create them and then set up Windows Hello.

You will get prompts to look into the camera with your head kept centred in the display. You are now ready to get started with the authentication feature. If you wear glasses, Microsoft recommends that you set up Windows Hello with your glasses on and off.

If you have bought either of the Surface units, do not forget to check the update. Following is the release note of the update, although it does not mention Windows Hello.

"Cumulative and current firmware and drivers for the Surface Pro 4. This firmware and driver package contains drivers for all of the components in the Surface Pro 4, as well as updates to the system firmware that have been released via Windows Update. These drivers and firmware are compatible with Windows 10, including Enterprise versions. The driver MSI and ZIP files include all of the drivers and firmware needed to deploy custom images of Windows on your Surface devices. Additionally, the WinTab driver is provided for those professionals needing WinTab compatibility with certain Surface Pen enabled applications."

Here are the download links for the updates: Surface Pro 4 ll Surface Book.