Managing Automatic Updates in Group Policy
Automatic Updates help you keep the operating system up to date. Although you can configure Automatic Updates on a per-computer basis, you’ll typically want to configure this feature for all users and computers that process a GPO-this is a much more efficient management technique.
Note that by default, Windows 8.1 and Windows Server 2012 R2 use Windows Update to download Windows Components in addition to binaries for roles, role services, and features. If the Windows diagnostics framework detects that a Windows component needs to be repaired, Windows uses Windows Update to download the component. If an administrator is trying to install a role, role service, or feature and the payload is missing, Windows uses Windows Update to download the related binaries.