Allow Automatic Updates immediate installation
Supported on: At least Windows XP Professional Service Pack 1 or At least Windows 2000 Service Pack 3 through Windows 8.1 or Windows Server 2012 R2 with most current service pack. Not supported on Windows 10 and above.
Registry
Software\Policies\Microsoft\Windows\WindowsUpdate\AU Value name: AutoInstallMinorUpdates
Enabled: AutoInstallMinorUpdates = 1
Disabled: AutoInstallMinorUpdates = 0
Description
Specifies whether Automatic Updates should automatically install certain updates that neither interrupt Windows services nor restart Windows. If the status is set to Enabled, Automatic Updates will immediately install these updates once they are downloaded and ready to install. If the status is set to Disabled, such updates will not be installed immediately. Note: If the "Configure Automatic Updates" policy is disabled, this policy has no effect.