In many company networks, the admins does not disable the admin shares by GPO. If you do not want to share your drives with everyone, here’s what to do on a Windows 7 machine.
Hit Windows ORB and type ‘REGEDIT‘, hit Enter
Navigate to the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
Create the new DWORD (32-bit) Value and in the name field type: LocalAccountTokenFilterPolicy
Leave the default value of 0.
or
Navigate to the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanManServer\Parameters
Create the new DWORD (32-bit) Value and in the name field type: AutoShareWks and press Enter. (You can also leave this setting with its default value of 0.)
Changes should be active after you close the registry editor, but just in case restart your PC.