Thanks a lot Crusty for your quick reply.
The Digital Director Link works fine. But in the case of Wrigley Video Production link whenever I click the red tutorial button for trying to download through Download Accelerator Plus it says "File Download could not completed successfully. Server has internal problem". It happens in all the cases of Wrigley Video Production tutorials. But in other cases Download Accelerator Plus works fine. Will you please let me know whether you are experiencing the same problem or not.