Windows hello can't open camera after windows 1809 update.

[DreamFinder308]

I recently received windows 10 update 1809 and now my windows Hello function has stopped working. It says it cannot start the camera. I see the camera lights flash but it does not turn on. If I run the camera app or any realsense program the camera works fine.

[Kripkee]

Here is what worked for me:  I had a similar problem on my HP Envy All-in-One 27-b1XX.  Until a couple of days ago, Windows Camera and Windows Hello were working fine.  Two days ago, I reinstalled Windows 10 64 Bit.  After the reinstallation, Windows Camera wouldn't work and Windows Hello couldn't find the camera.  I stumbled upon the following solution by modifying a suggestion  by Rafael Rivera that I found on this web page: https://www.winhelponline.com/blog/webcam-anniversary-update-windows-10-yuys-standard/ .  I modified this solution as follows:  In the registry at  

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Media Foundation\Platform  I created a DWord named EnableFrameServerMode .   However, instead of giving it the value 0 as recommended by Rafael Rivera, I gave it the value 1.  I did the same at HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows Media Foundation\Platform .  With these changes to the registry, both Windows Camera and Windows Hello work.

[Kripkee]

After a Windows Update on 04/03/2019, Windows Frame Server is broken again.  My Camera and Windows Hello both stopped working.  I was able to get both of them working again by changing a DWord in my registry from 1 to 2.  The DWord is 

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Media Foundation\Platform\EnableFrameServerMode

I have also changed another registry DWord to 2:

HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows Media Foundation\Platform\EnableFrameServerMode

[Kripkee]

I installed Windows 10 version 1903.  After the installation, Windows Hello, Camera and Windows Frame Server were working without the DWords in the registry for EnableFrameServerMode, so it appears that version 1903 resolved this problem.

However, HP Support Assistant invited me to install IR camera driver-Realtek, SoftPaq number sp78998, Version 10.0.10586.11226, which it describes as "the IR camera driver for Windows Hello."  I did this installation, and it promptly broke Windows Frame Server, Windows Hello and Camera.  Windows Frame Server crashed every time I tried to use Windows Hello, and Windows Hello told me that it couldn't find my camera.  Camera would not display an image.  I tried to fix the problem by using the EnableFrameServerMode DWord using the values 0, 1, 2 and 4 successively.  None of them worked.  I then used Windows Restore to back out the installation of IR camera driver-Realtek.  Immediately Windows Frame Server, Windows Hello and Camera worked again.

Conclusion:  IR camera driver-Realtek breaks Windows Frame Server in Windows 10 Version  1903.  Don't use it.

My PC is an HP Envy All-in-one 27-b1XX.