Initiate definition update on startup

This policy setting allows you to configure definition updates on startup when there is no antimalware engine present.

If you enable or do not configure this setting, definition updates will be initiated on startup when there is no antimalware engine present.

If you disable this setting, definition updates will not be initiated on startup when there is no antimalware engine present.

Supported on: At least Windows Server 2012, Windows 8 or Windows RT
Registry HiveHKEY_LOCAL_MACHINE
Registry PathSoftware\Policies\Microsoft\Windows Defender\Signature Updates
Value NameDisableUpdateOnStartupWithoutEngine
Value TypeREG_DWORD
Enabled Value0
Disabled Value1

windowsdefender.admx

Administrative Templates (Computers)

Administrative Templates (Users)