Precision Computing

Where's your ObPowershell to manipulate the group policy setting from PowerShell? :-)

Here's a reference that maps group policy settings to registry settings:

Group Policy Settings References for Windows and Windows Server
http://www.microsoft.com/downloads/details.aspx?FamilyID=18c90c80-8b0a-4906-a4f5-ff24cc2030fb&displaylang=en

Here's a PowerShell script that will create the registry value for 'No auto-restart with logged on users for scheduled automatic updates installations':

# Enable-WUNoAutoRebootWithLoggedOnUsers.ps1
# Sets Group Policy to prevent Windows Update from rebooting if a user is logged on.
New-Item -Path HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate\AU -Force
Set-ItemProperty -Path HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate\AU -Name NoAutoRebootWithLoggedOnUsers -Value 1

I've confirmed that it creates the same registry value as the Local Group Policy Editor, but for some reason the editor doesn't show it as enabled. I haven't received an update yet that requests a reboot, so the jury is still out on whether it is truly enabled... but it should work according to the reference I linked to above.

Correction to my last comment. The Set-ItemProperty line should actually use New-ItemProperty and set the value type to DWORD, as in the following:

New-ItemProperty -Path HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate\AU -Name NoAutoRebootWithLoggedOnUsers -Value 1 -PropertyType DWORD