How to remove Local Admin from all XP, Win 7, Win 8 but still allow users to copy files to C:\Oracle folder.

Hi,

I would like to remove the local admin privilege from all Clients PC's and laptops which includes Windows XP, Windows 7 & Windows 8 using GP.
But I still want the users to copy tnsnames.ora files to C:\Oracle folder on their local machines.
How is this possible to achieve such a configuration using GP?
TIA.
Liby