I had a server today that in the Group Edit Policy was missing some of the location items.
To add them back is rather simple.

Open Group Edit (Start->Run->gpedit.msc)
Right click on the "Administrative Templates"
Click "Add/Remove Templates"
You will see a dialog box pop up listing the current installed templates.
Click "Add", this will open a location dialog defaulting to "Windows\system32\inf" folder, it will show a bunch of .adm files. From the list add in Conf.adm and System.adm.
Close the Add/Remove Templates dialog box and you should now have the required options.