The system automatically creates hidden “administrative shares” for its logical drives C:, D:, and so forth which it names C$, D$ and so forth. It also creates the admin$ hidden share for to the \winnt or windows folder. These shares are designed for remote access support by domain administrators. By default, if you delete these admin shares, they will be recreated when you reboot. To disable permanently so they will not be recreated on the next reboot, use the following procedure.
Note:- Before doing this procedure please take a complete registry backup
For Workstations (Vista/XP/2000)
Click Start—>Run type regedit click ok
For vista users Enter your UAC credentials to continue.
Open the HKEY_LOCAL_MACHINE branch.
Open the SYSTEM branch.
Open the CurrentControlSet branch.
Open the Services branch.
Open the LanmanServer branch.
Select the Parameters branch.
Select Edit, New, DWORD (32-bit) Value. Vista adds a new value to the Parameters key (If you have the key just check for correct value).
Type AutoShareWks and press Enter. (You can leave this setting with its default value of 0.)
Restart Windows to put the new setting into effect.