I have finally got round to downloading Calibre and have managed to transfer all of my 97 books onto the programme, but it will not convert any of the books I have bought from Waterstones. When you buy from there you have to download their digital editions reader so the books should go straight into there, but I usually download them onto the desktop and drag them across. They download in a format called ACSM and Calibre does not recognise it so it cannot convert it. Any ideas? The books were cheap - they have lots on for £1.99 today, but I would like them all in Calibre now I see how straightforward it is. Help!