By default, Windows shares your all drives (C: shared as C$, D: as D$ and so on) so that you can access them over the network using your administrator password. However, if you’re the paranoid kind or need to share your admin password with your colleagues from time to time, you might want to turn off admin shares.
You can do this using the Sharing tab under the drive’s properties, but the shares are enabled again after you restart. For the permanent solutions, open the Registry Editor
( Start > Run > “regedit” > [Enter] ) and navigate to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanManServer\Parameters.
Right-click in the right-hand pane and select New > DWORD value. Call this DWORD “AutoShareWks”, and assign it a value of 0 (which it should be by default).
Restart your PC for the change to take effect.