With regard to my laptop PC, this is now O.K. After clicking on "Contents" the list of startup items was found to have numerous duplications. These were designated with (1) or (2) after the name. I have deleted all the duplicated items and now Speed Startup performs correctly. The defragmenter program is listed in the "Lineup" and works perfectly.
The same does not happen with my desktop PC. Ashampoo Magical Defrag is in the Lineup but it's icon does not appear in the notification area and the program fails to operate. I have e-mailed Ashampoo as I believe the problem is with the program.