Limit Local Access

To limit access to the local workstation, set the data value of the NoRun DWORD value to 0x1 in the following registry key:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
Setting this value disables viewing local files by typing a file address or URL (for example, "file://c:\") in the Address box, and also disables the Run command on the Start menu.
Setting this value also disables the ability to browse to the local file system using an embedded HTML link. For example, you cannot browse a file by clicking the HTML link provided by the My File System tag when this registry setting is used.

If you want to disable access to a drive altogether, set the data value of the NoDrives DWORD value as indicated:
Drive DWORD value ------------------- A 0x1 B 0x2 C 0x4 D 0x8