How to change Windows 10 login screen inactivity timeout?

We are developing some MFA (multi-factor authentication) support on Windows. After entering the user password it will have other challenge like email/phone calls.

But on Windows 10 we found that the login screen (not remote) will close after 30s of inactivity. In some cases the email/phone challenge may take more than 30s, and logon screen being closed will stop the email/phone wait.

Is there any way, like registry, to change the Windows 10 logon timeout value?

The registry controlling the login screen timeout is

Key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI

DWORD Value: IdleTimeOut

Unit: msec

Because the registry key wasn't here and adding it didn't work.

My windows versions (for info):

(Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\WindowsNT\CurrentVersion").ReleaseId

#1803

Get-WmiObject win32_operatingsystem | Select-Object caption, version

#caption                  version

#-------                  -------

#Microsoft Windows 10 Pro 10.0.17134

1. Get Your Scheme or use 'SCHEME_CURRENT' alias

Check your current power scheme:

powercfg.exe /LIST

#Existing Power Schemes (* Active)

#-----------------------------------

#Power Scheme GUID: 381b4222-f694-41f0-9685-ff5bb260df2e  (Balanced) *

#Power Scheme GUID: 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c  (High performance)

#Power Scheme GUID: a1841308-3541-4fab-bc81-f71556f20b4a  (Power saver)

Get your current scheme alias:

(powercfg.exe /QUERY ((powercfg.exe /GETACTIVESCHEME) -replace '.* ([0-9a-f-]{36}) .*', '$1'))|Select-String -Pattern "^  GUID Alias"

#GUID Alias: SCHEME_BALANCED

2. Set lock timeout AC or DC

Use /SETACVALUEINDEX when you are not on battery

Use /SETDCVALUEINDEX when on battery

The value is in seconds, so here 1200s = 60s * 20 i.e. 20minutes

powercfg.exe /SETACVALUEINDEX SCHEME_CURRENT SUB_VIDEO VIDEOCONLOCK 1200

https://stackoverflow.com/questions/39864379/how-to-change-windows-10-login-screen-inactivity-timeout/39978595#39978595