Hi Joe,
I know it sounds like an odd move but try enabling "Remove Run menu from Start Menu" under GPO > User Config > Admin Templates > Start Menu and Taskbar
I know the run option is not there on the Win 10 start menu so it seems like a dumb move but in the description for this GPO it states:
If you enable this setting, the following changes occur:
(1) The Run command is removed from the Start menu.
(2) The New Task (Run) command is removed from Task Manager.
(3) The user will be blocked from entering the following into the Internet Explorer Address Bar:
--- A UNC path: \\\
---Accessing local drives: e.g., C:
--- Accessing local folders: e.g., \temp>
Also, users with extended keyboards will no longer be able to display the Run dialog box by pressing the Application key (the key
with the Windows logo) + R.
Hope that does the trick for you
Olly