Microsoft has laid out a wide-ranging plan to overhaul its Windows software platform, marking a bid to stem the erosion of its core PC software business amid the rise of touchscreen computing touched off by Apple.
Along with the first full touchscreen version of Windows, the world's biggest software company on Tuesday showed off an array of other technology tools and online services to buttress its Windows system in the era of tablet computing.
These included an online store for users to find and download lightweight "apps", a new way for developers to write software to run on Windows, and versions of its software to run on devices such as tablets that enjoy longer battery life.
"A new way of using computing has arisen, and we want Windows to respond to that," said Steven Sinofsky, president of the Windows division.
The announcements, made before an audience of more than 5,000 software developers at a Microsoft event in California, were designed to win back attention for Windows at a time when many software developers have switched to building apps for devices such as the iPhone and the iPad.
Products based on the new technology are not expected until the middle of next year at the earliest. However, the response to the broad plan laid out on Tuesday has been seen by Wall Street as a key test of Microsoft's ability to counter the rise of the Apple and retain its wider sway in the software world. The number of PCs sold in the developed world fell by more than 10 per cent in the first half of the year as smartphone sales boomed and the iPad grabbed a foothold.
Tuesday's presentation included the first full demonstration of the forthcoming Windows 8, which will combine a touchscreen interface with the more traditional mouse-and-icon approach of PCs. Developers would be able to create new types of software that will let users combine touch with other ways of interacting with machines, said Mr. Sinofsky.
Central to the new Windows platform is a touchscreen interface known as Metro that is based on large "tiles", similar to those already used in Microsoft's smartphone software.
Hints in recent months about the new software frameworks that will be used to write apps for Metro have caused unease among many developers, who have invested in a different set of technology tools traditionally used to build software for Windows. Showing off the new tools, Microsoft executives said they would make it easier to build a new generation of web-based apps that can operate on all of its devices.
Users "don't want apps to stand alone, they want a web of apps," Mr. Sinofsky said, in a jab at the "native" apps that are downloaded on to Apple devices.