Under the Hood

Of all the changes in Windows XP, the biggest one is invisible to the eye. The guts of Windows XP aren't the same guts that were in Windows 9X/Me. Instead, Windows XP uses the underlying engine that is used in the Windows 2000 operating system. If you ignore IBM's old OS/2 Warp (and most people did), this marks the first time a corporate-grade OS has been made available to home users.

A True 32-Bit Operating System

All previous Microsoft home operating systems have evolved from the old 16-bit MS-DOS operating system. The very first version of Windows wasn't much more than a pretty face—a graphical user interface, or GUI—grafted onto the underlying DOS command structure. Subsequent versions of Windows improved on the original, but still retained the original MS-DOS underpinnings. This was done to ensure compatibility with older applications and believe it or not, a fair number of DOS-based applications are in use today.