Server 2008 Group Policy Administrative Templates Explained
Group Policy administrative template contains collection of settings / registry keys for user configuration or computer configuration. ADM files are used in Server 2000 / 2003 environment. Server 2008 and Windows Vista use ADMX and ADML files.
When GPO is created by Server 2003 Windows XP tools, it creates set of ADM files in the SYSVOL GPO folder. In Server 2003, each GPO has copy of the same common template files within each GPO folder. If existing GPO is opened for viewing or editing, ADM files are compared and newer version is copied to SYSVOL GPO folder. As you may have guessed, this can cause a lot of problems in large Active Directory environments. For example, if an administrator using Windows XP SP2 view the GPO that was created using Windows XP SP1, ADM template will automatically get updated. Then the domain controller would replicate the changes to all domain controllers. This feature can be turned off by configuring the domain GPO, under User Configuration\Policies\Administrative\Templates\System\Group Policy\
A lot of changes are made to Group Policy in Server 2008 and Windows Vista. The ADM files are not split into two files—ADMX administrative template settings file and ADML administrative template language file. GPO created by Server 2008 or Windows Vista Group Policy Management tool creates ADMX file and not the administrative template files as in Server 2003. This reduces the size of SYSVOL folder and save replication bandwidth. So when a GPO is created by the Windows Vista Group Policy Management Console, GPO folder makes use of the ADMX/ADML files. When a GPO is created by Windows XP and Windows Server 2003 Group Policy tools, it copies the ADM files to SYSVOL GPO folder.
Screenshot of ADM files
Screenshot ADMX files
