Windows Update can't be readily disabled in Windows 10 Home, and the license terms that all users must agree to allow Microsoft to install updates automatically.
The Insider Preview releases of Windows 10 didn't include any way to prevent Windows Update from downloading and installing updates, but it wasn't clear if this was just some quirk of the previews, or the long-term plan; Microsoft's previews often have special rules for things like providing automated feedback and hooking up online services, and so this could have been part of that.
Build 10240, released to insiders on Wednesday, changes that. This build is believed to be the release-to-manufacturing build that OEMs will preinstall on hardware, and as such, it contains the finalized settings, license text, and so on.