Stop Windows Update from Rebooting in the Middle of Work

**Get-ItemProperty** on the WindowsUpdate policy key shows the active hours and the auto-restart settings. A managed device may have them pinned by group policy.

Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\WindowsUpdate\UX\Settings' | Select-Object ActiveHoursStart,ActiveHoursEnd,SmartActiveHoursState,IsExpedited
Get-ItemProperty 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU' -ErrorAction SilentlyContinue | Select-Object NoAutoRebootWithLoggedOnUsers,AUPowerManagement

Windows will not restart during active hours. The window can be up to 18 hours, which covers a normal working day.

Set-ItemProperty 'HKLM:\SOFTWARE\Microsoft\WindowsUpdate\UX\Settings' -Name ActiveHoursStart -Value 7 -Type DWord
Set-ItemProperty 'HKLM:\SOFTWARE\Microsoft\WindowsUpdate\UX\Settings' -Name ActiveHoursEnd -Value 23 -Type DWord
Set-ItemProperty 'HKLM:\SOFTWARE\Microsoft\WindowsUpdate\UX\Settings' -Name SmartActiveHoursState -Value 1 -Type DWord
Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\WindowsUpdate\UX\Settings' | Select-Object ActiveHoursStart,ActiveHoursEnd,SmartActiveHoursState

**RestartNotificationsAllowed2** enables the toast that offers a choice instead of a countdown. Without it, Windows restarts as soon as the grace period ends.

Set-ItemProperty 'HKLM:\SOFTWARE\Microsoft\WindowsUpdate\UX\Settings' -Name RestartNotificationsAllowed2 -Value 1 -Type DWord
Set-ItemProperty 'HKLM:\SOFTWARE\Microsoft\WindowsUpdate\UX\Settings' -Name IsContinuousInnovationOptedIn -Value 1 -Type DWord -ErrorAction SilentlyContinue
Start-Process ms-settings:windowsupdate

The policy **NoAutoRebootWithLoggedOnUsers** blocks the automatic restart while anyone is logged on. It is a blunt tool, and it is the right one for a workstation that runs long jobs.

New-Item 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU' -Force | Out-Null
Set-ItemProperty 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU' -Name NoAutoRebootWithLoggedOnUsers -Value 1 -Type DWord
Set-ItemProperty 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU' -Name AUPowerManagement -Value 0 -Type DWord
Get-ItemProperty 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU' | Select-Object NoAutoRebootWithLoggedOnUsers,AUPowerManagement

A pending update with a short deadline forces the restart regardless. Knowing it is there lets you install it on your own terms.

$s = New-Object -ComObject Microsoft.Update.Session
$sr = $s.CreateUpdateSearcher()
$sr.Search('IsInstalled=0 and IsHidden=0').Updates | Select-Object Title,IsDownloaded,Deadline
Get-WinEvent -LogName 'Microsoft-Windows-WindowsUpdateClient/Operational' -MaxEvents 15 -ErrorAction SilentlyContinue | Where-Object Id -in 19,43,44 | Select-Object TimeCreated,Id,Message -First 5

After a scan, the settings page should show a restart time outside the active hours, or an explicit schedule. If it still shows a countdown, a policy is overriding it.

usoclient StartScan
Start-Sleep -Seconds 30
Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\WindowsUpdate\UX\Settings' | Select-Object ActiveHoursStart,ActiveHoursEnd,RestartNotificationsAllowed2
Get-Service wuauserv | Select-Object Status,StartType