To remove administrative shares by editing the registry
To remove administrative shares and prevent them from being automatically created in Windows:

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 (http://support.microsoft.com/kb/322756/ ) How to back up and restore the registry in Windows

1. Click Start, and then click Run.
2. In the Open box, type regedit, and then click OK.
3. Locate, and then click the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters\AutoShareServer
Note The registry key AutoShareServer must be set as type REG_DWORD. When this value is set to 0 (zero), Windows does not automatically create administrative shares. Note that this does not apply to the IPC$ share or shares that you create manually.
4. On the Edit menu, click Modify. In the Value data box, type 0, and then click OK.
5. Quit Registry Editor.
6. Stop and then start the Server service. To do so:
1. Click Start, and then click Run.
2. In the Open box, type cmd, and then click OK.
3. At the command prompt, type the following lines. Press ENTER after each line:
net stop server
net start server
4. Type exit to quit Command Prompt.