TIEPortableDevices.CanNavigateToParent
 
Declaration
property CanNavigateToParent : Boolean; (read-only)
Description
Returns true if there is a parent of the 
active folder. I.e. so that 
NavigateToParent will succeed.
// Enable the "Go Up" button if there is a parent of the current folder
btnOpenParent.Enabled := IEPortableDevices.CanNavigateToParent;