1. Go to the location in the Group Policy listed above.
2. Right-click File System.
3. Click Add File.
4. In the "Add a file or folder" window, select the folder (or file) for which you want the permissions to be set, and click OK.
5. In the security box that pops up, you can add a user or a group that needs permission to the folder.
6. You can also configure permission inheritance if you want. If you decide later to modify the permissions or inheritance, simply right-click the object in the right-hand pane and select Properties.

There's one thing that you must keep in mind: Although the path to the file or folder is, by default, pointing to the folders on the server, the path is relative to the client to whom this Group Policy will be applied. Simply type the path to the folder in the text box if you don't see the folder you need listed there.