TIEPortableDevices.LastError
 
Declaration
property LastError : String; (Read-only)
Description
Returns detail on the last failure that occured.
When calling a WPD method, such as 
NavigateToFolderID, a false result will indicate failure. Read 
LastError to access detail of the failure.
             
if IEPortableDevices.RefreshDevices = False then
  ShowMessage('Unable to get devices: ' + IEPortableDevices.LastError);