Disable Windows 10 Upgrade notice via GPO

To disable the Win 10 upgrade notification via group-policy preference, on the OU housing the attached clients create a group-policy preference Registry item to define the DisableGWX value.

Always make sure registry/system backups are available prior to adjusting/creating registry values.

Creating a Registry item
To create a new Registry preference item

    Open the Group Policy Management Console . Right-click the Group Policy object (GPO) that should contain the new preference item, and then click Edit .

    In the console tree under Computer Configuration or User Configuration , expand the Preferences folder, and then expand the Windows Settings folder.

    Right-click the Registry node, point to New , and select Registry Item .

    In the New Registry Item dialog box, select an Action for Group Policy to perform. (For more information, see "Actions" in this topic.)

    Enter registry settings for Group Policy to configure or remove. (For more information, see "Registry settings" in this topic.)

    Click the Common tab, configure any options, and then type your comments in the Description box. (For more information, see Configure Common Options.)

    Click OK . The new preference item appears in the details pane.

Actions

This type of preference item provides a choice of four actions: Create , Replace , Update , and Delete . The behavior of the preference item varies with the action selected and whether the registry key or value already exists.

The specific preference you will want to add is this:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Gwx

Right-Click and create a new 32-bit DWORD value called "DisableGWX" and assign it a value of 1

https://technet.microsoft.com/en-ca/library/cc753092.aspx?f=255&MSPPError=-2147217396
www.howtogeek.com/218856/how-do-you-disable-the-get-windows-10-icon-shown-in-the-notification-tray/

Thanks for the comment. I already knew how to do this. I was more interested why some servers didn't have the setting in the GPO already.

Server products cannot be upgraded to windows 10 which is a client operating system. They will not install the windows update to upgrade to windows 10 and you should not get any  Windows 10 upgrade notices

That setting will only be seen if you use RSAT on win10 v1511 and connect to your servers.

Why don't servers have this.. THEY DON'T NEED IT.  Windows 10 is a CLIENT operating system.  

For your information, Microsoft is desperately trying to reduce their costs in supporting outdated operating systems. i.e. Windows 95 didn't support USB, versions prior to Windows 8 don't support USB3 natively. It is immensely expensive to support everything from Vista/Server 2008 onwards. Every security patch has to be tested on each O/S in many configurations.

The industry has historically supported an upgrade path.  Apple was the first to break this mold when they dumped PowerPC and went Intel. Android doesn't support upgrades to 2.2 or older and most AOSP apps are not supported (Google is slowly dropping support of AOSP devices and requiring an Android license.

Ok so I will have to use RSAT to set the GPO on non 2012R2 servers. Thanks for the info. It save me the time of trying to find the KB download for the server.