If you want to disable the display of local or networked derive for privacy and security purpose, you can follow the following procedure to do so.
To disable the display of local or networked drives when you click My Computer.
1.Go to start->run.Type regedit.Now go to:
Now in the right pane create a new DWORD item and name it NoDrives (it is case sensitive). Now modify it's value and set it to 3FFFFFF (Hexadecimal) . Now restart your computer. So, now when you click on My Computer, no drives will be shown(all gone...). To enable display of drives in My Computer, simply delete this DWORD item that you created.Again restart your computer.You can now see all the drives again.