Thanks everyone for your help.
As per my preference I did not want to put non-standard firmware on the machine, so took the suggestion of formatting the storage.
Not sure exactly what I was meant to do, but having connected the USB cable shortly after a soft reset, I formatted the data drive that Windows told me I had just connected. This meant that the Reader got past the "starting up" screen
but I still had problems copying books over. I then tried the "Format Internal Memory" option on the reader, that also created a couple of folders on the relevant drive when viewed in Windows. And now it seems to all be sorted - so thank you all for your help.
One of the main things that I hadn't really appreciated the significance of was the difference between the internal memory (that you can easily format) that just stores stuff like books (and perhaps tunes and pictures) and the system memory that stores the operating system for the Reader. In retrospect I should have done the "format" earlier, but did not realise that this was NOT going to affect the operating system of the device.
My long reply here is just to hopefully help others in the same situation!
Once again - big thanks
