Microsoft's new operating system, Windows XP, is the company's most important new product since Windows 95 and is being targeted chiefly at the consumer market.

Some questions and answers about Windows XP:

Q: Why would I want to upgrade?

A: Windows XP has a more stable programming code than the one on which the business-oriented Windows 2000 was built, meaning your computer is much less likely to crash. Windows XP also includes more user-friendly features than ever: a souped-up music and video player, digital photo editing capabilities and real-time text, voice and video communications. It has better networking support and added security features. Windows XP is also more closely linked -- and likely to promote -- other Microsoft products such as the company's Web services.

Q: How much does Windows XP cost?

A: Windows XP Home Edition costs $99 to upgrade from a previous version of Windows, or $199 to buy new. The Professional Edition, which includes additional security and networking features unnecessary for the vast majority of consumers, costs $199 to upgrade, or $299 new.

Q: What hardware do I need to run Windows XP?

A: Computers less than two years old should support Windows XP without hardware upgrades. Microsoft recommends at least a 300 MHz Intel Pentium II or compatible processor, 128 megabytes of RAM and a CD-ROM drive. A standard installation requires 1.5 gigabytes of hard drive space.

Q: Will my other electronic devices and favorite software work with Windows XP?

A: To find out if your current setup is compatible, go to www.microsoft.com/windowsxp and take a compatibility test. It is also a good idea to check the Web sites of your favorite products for updates. Some companies may release drivers to make your favorites work with Windows XP over the next few months. You will need to buy new versions of your security software, such as virus and firewall protection, if you upgrade to Windows XP. Analysts are also warning you might have trouble running peripherals that were built before 1999 or were made by start-ups that have since gone out of business.

Q: How might this new release be affected by the federal court rulings that found Microsoft engaged in monopolistic behavior, and the planned penalty hearings?

A: Windows XP contains many added features that are an issue for competitors and several state attorneys general who have sued the company. The product's Internet-oriented tools, such as the Passport authentication service, also trouble critics worried that Microsoft may be trying to extend its dominance in operating systems into other areas. Windows XP remains an issue in the antitrust trial. Microsoft contends it is merely giving consumers what they want and maintaining its freedom to innovate by adding a raft of new features to Windows XP. It is possible that penalties in the antitrust case may touch on Windows XP, but they are unlikely to be imposed anytime soon.