Access denied for a file on a local computer on a Domain

I need to provide full access for a folder which is a subfolder of the C:\program files directory of each local machine in my domain. Although I could manually configure this on each machine I would prefer to do this with a group policy on our server 2008 R2. Other group policies are working but the one I have written to change this setting doesn't work. Any pointers as to anything else I need to configure would be appreciated.