disable default share C$

Create the AutoShareServer and AutoShareWks registry values and  set to 0

running as following;

1. Click Start, click Run, type regedit, and then press ENTER.
2. Locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanmanServer\Parameters 
3. Create  AutoShareServer and AutoShareWks DWORD values in the LanmanServer\Parameters subkey are configured with a value data of 0. 
4. Quit Registry Editor.