So from
http://www.pcworld.com/article/20286...nt-format.html
What you should realize is that PC World is missing a key bit of info. While MobileRead is where support for calibre is found, and is full of many people who are very passionate and willing to help out, the extra zip they have you download is from a third party "Apprentice Alf" and is used to remove DRM (copy protection) from books. Unfortunately, for legal reasons NO discussion of the DRM removal tools is allowed here. Search for "Apprentice Alf" in Google and ask for help there.