There are a few places to stop Automatic Updates, but they all depend on the Automatic Updates Service to be running to work.
Disable the Automatic Updates Service and it all stops.
Start>Run>Services.msc>Automatic Updates>>> Double-Click and click dropdown box, select "Disabled" then click "Stop" Then click Ok.
Also, to speed up boot-time, Start>Control Panel>System>Automatic Updates(tab)>"Turn off Automatic Updates"
This prevents Windows from trying to start the service at boot-time, wasting time, and keeps this error out of the event viewer.