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 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
Windows NT registry hack:
Hive: HKEY_LOCAL_MACHINE
Key: SYSTEM\CurrentControlSet\Services\LanManServer\Par ameters
Name: AutoShareServer for servers
Name: AutoShareWks for workstations
Type: REG_DWORD
Value: 0

Thanks,

I know about this sharing of drives like C$ ... But I did not know about admin share...

That;s good information you gave that how to disable this sharing

Thanks again,...