I have now managed to crash the PC with my Cool-er.
Don't try to switch the PC on with the Cool-er attached via the USB cable, else the PC never boots up!
The selection of 100 free books from the Elonex reader site is quite different from the Sony's 100 free books. There are a lot of Dickens, Shakespeare, Conan-Doyle etc, but some other different authors - in fact more to my taste, so I'm pleased to have found them to add to my Cool-er.
They are all in html or txt format, though.