i want to disalbe sharing root drive (only C$, D$ , .... but not administrative defult share ) with gpo in windows server 2008

Hi

I have network with 400 client computer runnig windows xp , and server 2008 with domain controller .

  I want to enable sharing admin$ , ipc$ ,... but not share C$,d$,...... for my workstation.

i do AutoShareWks"=dword:1 in registry but all item shared (admin$, c$ , D$ , ...).

how can i do it.