Windows XP is composed of 40 million lines of computer code, scattered across your hard drive in thousands of files. The vast majority of them are support files, there for behind-the-scenes use by Windows and your applications. They're not for you. They may as well bear a sticker saying, "No user serviceable parts inside."
That's why the Start menu is so important. It lists every useful piece of software on your computer, including commands, programs, and files. You can use the Start menu to open your applications, install new software, configure hardware, get help, find files, and much more.
When you click the Start button at the lower-left corner of your screen, the Start menu pops open, shooting upward. Its contents depend on which options you (or your computer's manufacturer) have put there; Figure 2-4 illustrates an example. The new, multi-column structure of the Start menu is one of the most radical developments in Windows XP.
The new Start menu is divided into four chunks. One area, the pinned items list, lists programs you use every day and is yours to modify. Another, the most frequently used programs list, lists programs you use often and is computed automatically by Windows. The final two sections list Windows features and standard Windows programs. Figure 2-4 describes the function of each section.