An operating system for computers, it is designed to run Microsoft Windows software applications on PCs. There are several versions, including Windows 95, Windows 2000, Windows Me (Millennium edition), and Windows XP. Windows 95 represented a significant advance over its precursor, Windows 3.1. It featured a snazzy new GUI (which at the time looked suspiciously similar to the Macinterface), plug-and-play capabilities, long file names, built-in network support, improved handling of system resource problems, and most importantly for techies, support for 32-bit applications (meaning that apps written specifically for Windows 95 could run much faster). It became so popular that it essentially replaced DOS as the most common underlying platform.
XP, an operating system introduced by Microsoft as part of its Windows family of operating systems, is said to be Microsoft's most important product since Windows 95. Basically, XP has a new look and feel, and its environment is more stable. It is designed to support plug-and-play, and it will work with wireless networks. There are two flavors: the Home version (which emphasizes digital music, digital video, and home networking) and the Professional version (which emphasizes security).