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Preston Gralla is the award-winning author of more than 30 books, including How the Internet Works, Windows XP in a Snap, the Complete Idiot's Guide to Internet Privacy and Security, The Complete Idiot's Guide to Buying a PC, How to Expand and Upgrade PCs, and The Complete Idiot's Guide to Online Shopping. He has written about computer technology and the Internet and has been a columnist for many magazines, Web sites and newspapers.