On further investigation of previous post(s), I have now learned that Microsoft has an update for Windows Update and Group Policies.
Basically, there is an update that should be installed on Domain servers and workstations that will add the option to turn of Upgrades/Updates to new versions of Windows.
Info about this and about GPO settings:
This is better than scripting your way around the problem, unless you have standalone workstations.
Hope this helps you, have fun!