This may not work for you, but this has fixed my Hello camera issues twice now. Once after the latest round of updates broke it and once after Microsoft Support broke it again by reinstalling the latest drivers. 1) Download the latest driver package with all of the Surface Book drivers in it from Microsoft. Download the .ZIP version and unzip it somewhere on your hard drive. 2) Go into Device Manager and under System Devices right-click on Surface Camera Windows Hello and select Uninstall. When the confirmation dialog comes up, check the box to remove the drivers from the system. 3) Once that completes, Scan for Hardware Changes. If the Surface Camera Windows Hello reinstalls itself, it will have done so with older drivers. Repeat step 2 to get rid of them too. Then do another Scan for Hardware Changes. 4) You should now have an Unknown Device with a yellow exclamation mark next to it. This is good and is what we need. 5) Go to where you unzipped the driver files, find the Drivers\Camera\WindowsHello folder and right-click on the SufaceCameraWindowsHello.inf file and select Install. The unknown device should disappear from Device Manager and the Surface Camera Windows Hello device should be back under System Devices. Your Windows Hello should now work every time as it did before. I can't, obviously, promise that this will work for everyone, but it has consistently taken care of the problem for me. YMMV P.S. Sorry. I didn't think to post the final working driver version. It is version 220.127.116.11 dated 10/2/2015. Be aware that after install, when you look at the Properties on the General tab under Device Status it will state, "No drivers are installed for this device." This is apparently normal for this driver.