I do not need to synchronise with iCloud, I just need to be able to open and work with files directly from the iCloud Drive, just like any other drive. I can access iCloud Drive easily through a browser, and that is good, but having to download for editing, then remembering to upload the edited version after ditching/renaming the original, is a bit of a pain - which of course I don't have to suffer when using my Windows machines. I've tried the link provided by one of the responders but no luck I'm afraid - I had been there before and not found the answer. It seems El Capitan will not go on this machine. (I have set Time Machine running now - closing the stable door etc., but it should stop any more horses bolting.) I did not run backups, do I suppose I deserve all I got. It's reassuring to know that there is so much speedy help out there.