Think you know Microsoft Windows inside out? Think again.

For more than a decade, power users have obsessed over ways to make Windows run faster, work smarter, and crash less often. Through books, magazine articles, and the Web, Windows users have amassed huge collections of keyboard shortcuts, registry hacks, elegant workarounds, and undocumented secrets to help master each succeeding Windows version. And now that Microsoft Windows XP has arrived, much of that hard-earned knowledge is irrelevant or obsolete.

Sorry to have to deliver the bad news, but it's true: From top to bottom, Windows XP is dramatically different from previous Windows versions. The more you think you know about Windows, the more likely you'll feel at least a little disoriented when you begin working with Windows XP. That's especially true if you've spent the past few years mastering Windows 95 and its successors, Windows 98 and Windows Me (Millennium Edition).