How? Ive tried group policies and the like and nothing seems to stick.

You can disable the update service. It works since at least Windows 98 and takes maybe 5 clicks.

I think you can't after the anniversary update

Maybe there is another Windows versions difference I am not aware of.

In my configuration this is still working. I went to services.msc and searched for "Windows Update". I stopped the service, went to its preferences and selected "Disabled" as startup type.

Pro 10 user here. Windows started wanting to update last week, but isn't because my group policy is set to notify for download and auto install, so all i had for the duration of the conference i was at was a notification.

It works fine.

It works in Pro, but not in Home and I think not in Enterprise either.

An officially supported channel that will let you select important security updates to install if and when you want to and not push anything else? Without relying on enterprise management features and the like? That would be interesting news to a lot of people, I'm sure, so please share what you know.

Disable updates then you can use http://www.windowsupdatesdownloader.com/