For users which really want to prevent Windows 10 from automatically installing updates, here are some methods to disable automatic updates. Depending on which method you use, you will still be able to manually check and install updates, or not be able to install updates at all...

Note that the methods leverage group policies, which is not supported on Windows 10 "Home/Essential" editions. A minimum of Windows 10 Pro or better is needed.

Caution

It is generally not recommended to disable automatic updates. Doing so (and not subsequently regularly installing the updates yourself) increases the risk of data loss and/or stealing due to potentional vulnerabilities in Windows 10.

Disable auto-update via registry:

The following is in fact a registry "hack" to simulate the presence of a GPO telling the system to disable automatic updates. You can still manually check for updates and install them.

1. Start regedit.
2. Navigate to the key: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
3. Create the following DWORD-values:
   • NoAutoRebootWithLoggedOnUsers(DWORD) = 1
   • NoAutoUpdate (DWORD) = 1
4. I also found mentions about creating an additional registry value at the same location:
   • AuOptions (DWORD) = 2
5. Reboot for the changes to take effect (or run gpupdate /force)

Alternate method

This alternate method is done through a GPO and effectively disables internet access for automatic updates. You can create a domain policy or use gpedit.msc to edit the local computer policy.

Note that this will disable manual updates too!

1. Create a GPO (or edit an existing one)
2. Navigate to Administrative Templates > System > Internet Communication Management > Internet Communication Settings
3. Find the setting Turn off access to all Windows Update features and enable it.
4. You may need to reboot for the chances to take effect.