Windows 10 offers less UI control over the updating behavior of the operating system than previous versions of Windows , There is no option to turn off Windows Updates using the Control Panel or Settings app in Windows 10, it checks for updates automatically and install any updates they find, whether you like it or not.
To completely block all updates of Windows 10 use Windows Update Blocker tool.
How it works? Just download Windows Update Blocker – it’s freeware program and run it.
Here you can download Windows Update Blocker and get full instruction how to completely disable update of Windows 10.