There is some improvement: we can now look at the files when we plug it into the computer, including my downloaded books. Unable to leave well enough alone, we ran CHKDSK on it with the /F switch. So they said it would have to be referred to a higher level of tech support.
They suggested doing a 'reset to factory defaults' but that made no difference. I pressed Cancel, and because it spooked me, immediately unplugged the reader, which then said 'No books found.' Even worse, when I tried plugging it into other computers I couldn't read anything on it: I got the message: 'The file or directory is corrupt and unreadable.'
I got a message saying I needed to format the drive. I plugged the reader into a computer which didn't have the desktop application installed.