Windows 2008 Server - missing system.adm file, editing system.adm file to restrict access to drive letter Options

[Hippiekiller]

I was looking at creating a GPO for a new OU i created for our domain.
The server is Windows 2008 Server standard.
I found this online Using Group Policy Objects to hide specified drives
I had a read and it seemed straight forward enough, but I cannot find the system.adm file on the server?

Am I missing something here?
I also opened up the GPO Management Editor when typing my post and the wording for the Admin Templates has "(ADMX)" in it, so i searched for the system.admx file but couldn't find that either

I have created an OU which will contain a couple of users who log onto our server remotely.
I would like to create a group policy which locks the server down so they can only run 2 applications.
I'm confident I have locked the server down enough using the options in the "User Configuration > Policies > Administrative Templates: Policy definitions" section.
But I would like to edit the system.adm file so that I can add some drive letters that are not available via the default options in the "Hide these specified drives in My Computer" or "Prevent access to drives from My Computer" settings.....

Any help would be appreciated on this.

[Hippiekiller]

All good, I got it sorted by simply using Not showing My Computer or in fact any links to explorer.
So system is nicely locked down like a KIOSK PC, which makes me think there is probably a GPO out there specifically for internet cafe / KIOSK PC's I could have used. lol