I did find some Windows Update options, but nothing that changed the automatic restart.
Well then, try this:
Right click on the Windows icon in the lower left screen.
Choose "Control Panel"
When the control panel opens up, choose "Administrative Tools"
When the Administrative Tools windows appears, double left click on "Services" listed in the right hand window
Scroll down the list until you see "Windows Update"
Double left-click on it, and make the changes I described earlier to change the start setting to "Manual"