Administrative Templates showcase the flexibility of Group Policy. Rather than being a static bundle of settings that can be changed inside the operating systems, all of the settings that are available inside GPME under the Admin Templates heading are settings that are being pulled from template files. The template files are .ADMX files that reside on your Domain Controller servers.
These ADMX files contain the information that the GPMC needs to display the available configuration settings in a friendly manner. There are primarily three important pieces of information inside ADMX files: the name of the settings, the registry key(s) that the setting is going to modify do its job, and a description for how it should look and work inside the Editor. Things such as what options it needs to have, drop-down boxes needed, what the description fields should say, and so on.
ADMX files are language-agnostic, so each ADMX file has an accompanying ADML file that defines the language for those settings.
Now, before we get too far I will point out that for Windows XP and earlier, these file types did not exist. The settings inside Administrative Templates were based on ADM files instead. But, as we have already stated, this book really pertains only to Windows 7 or newer, since in our organizations we should only ever be dealing with operating systems that are still currently supported by Microsoft. Heck, Win7 is going to fall out of support before we know it! ADMX and ADML files combine to create setting configuration options for the Group Policy Editor. These templates are the secret sauce that causes the settings to magically appear inside GPME.
We will look much further into the practical application of ADMX and ADML files in Chapter 8, Group Policy Maintenance. This is an area of Group Policy that you could be dealing with often, and adding new templates is technically digging under the hood of Group Policy a little. So, we will save the details for later. For now, a quick screenshot will show you that sitting on the hard drive of my Domain Controller is a folder containing all of my ADMX files. These files contain all of the information that is telling GPME how and what to display inside the Administrative Template settings groups:
