A. If you type "C:" (or any other drive) in the Microsoft Internet Explorer address box you will be shown the contents and if proper NTFS file permissions are not in place users will be able to delete, rename, read any files on the disk. This is usually a problem if you have a locked down environment where users do not normally have access to Explorer etc (such as an Internet Cafe).

To stop the ability to view local drives from Internet Explorer perform the following:

  1. Start the registry editor (regedit.exe)
  2. Move to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
  3. From the Edit menu select New > DWORD value.
  4. Enter a name of NoRun and press Enter
  5. Double click the new value and set to 1. Click OK to close the value edit dialog.
  6. From the Edit menu select New > DWORD value.
  7. Enter a name of NoDrives and press Enter
  8. Double click the new value and set to a number representing the drives you wish to hide (explained below). Click OK to close the value edit dialog.
  9. For IE 4.01 SP1 and above perform the following steps:
    1. From the Edit menu select New > DWORD value.
    2. Enter a name of NoFileUrl and press Enter
    3. Double click the new value and set to 1. Click OK to close the value edit dialog.
  10. Close the registry editor

The NoRun setting disables viewing local files by typing a file address or URL (for example, "file://d:\") in the Address box, and also disables the Run command on the Start menu.

The NoDrives setting disables the selected drives. It is explained in 'Q. How can I hide drive x from users?'. Basically drive A is 1, B is 2, C is 4, D is 8 etc. and you add the values together. So to hide drive C and D, you would add 4 and 8 which is twelve or C in hexadecimal and set NoDrives to C (selecting Hex mode).

Additional restrictions can be applied to IE 4.01 Service Pack 2 and IE 5.0 which are described in 'Q. What addition restrictions are available in Internet Explorer IE4.01 SP2 and above?'