Somehow this escaped our notice during the proof phase, but the hosts file that's printed in the book (and burned on the CD-ROM) is completely bogus. It actually blocks a number of very good sites that have anti-spyware software and even blocks MVPS.org, the place where you can get a real spyware/adware blocking hosts file.
So please ignore the file in the book, and our apologies to anyone we might have offended. Instead, get the regularly-updated spam and ad blocking hosts file from MVPS. You'll be happy you did!