Microsoft Corporation has unveiled its latest attempt to extend its seemingly omnipresent Windows operating system to one of the few places it hasn't already conquered -- the automobile.

The software, announced at the Convergence 2000 conference in Detroit, is designed to power the growing number of in-vehicle computers which auto manufacturers and aftermarket suppliers are installing in cars and trucks. The new operating system is the first part of Microsoft's Car.Net framework to be released.

The company hopes that third-party developers will use it to build mobile applications to deliver Internet and other communications services to vehicles. The service will be delivered through the Mobile Productivity Center, which connects a traditional cell phone and a Palm V hand-held computer to the vehicle's audio system. It will enable drivers to access e-mail, news, sports scores, and other Web content through voice commands.

The new software is the third version of Microsoft Windows CE for Automotive. The first version was used in the Clarion AutoPC, a voice-controlled device that combined elements of a car stereo, cell phone and personal digital assistant.

The second version will be used in the Internet computer General Motors plans to install on some Cadillacs later this year. After the first generation AutoPC all but disappeared in a field dominated by more user-friendly systems, Microsoft has decided to abandon the hardware portion of the automotive PC market and stick to what they do best -- making operating systems, according to industry observers.

Analysts predict that by 2006, 50 percent of new cars -- and 90 percent of luxury vehicles -- will have some kind of Internet capability. Dozens of automakers and electronics companies are vying for position in the promising market.