Use the Customize menu to specify a virtual root,
  a directory where you want to start displaying the
  namespace. You can also use this menu to save the list
  of virtual roots from one Browser session to another by
  choosing Save Virtual Root Settings.

  The virtual root is useful if you have interest in
  setting your starting point at a particular directory
  in the namespace or if you do not have read access to
  the root directory (/.:) when the Browser first starts.
  To display and expand a directory to which you do have
  read access, specify its name as the virtual root.