Microsoft launched a radical redesign of its world-dominating Windows operating system on Thursday, introducing a touch-enabled interface that attempts to bridge the gap between personal computers and fast-growing mobile devices powered by the company's fiercest competitors.
The debut of Windows 8 heralded the biggest change to the system since 1995, when the company first offered built-in Internet support.
And with so much riding on it, the overhaul could be Microsoft's most important product since co-founder Bill Gates won the contract to build an operating system for IBM Corp.'s first PC in 1981.
To succeed, the new version will have to be innovative and elegant enough to attract consumers who've fallen in love with notebook computers, tablets and smartphones running software from Apple and Google.
"What you have seen and heard should leave no doubt that Windows 8 will shatter the perceptions about what a PC really is," Microsoft CEO Steve Ballmer crowed at a New York event to kick off the Windows promotional campaign.
The first PCs and other devices running Windows 8 were to go on sale Friday.
Text: Michael Liedtke and Peter Svensson, Associated Press Technology Writers
Image: Microsoft CEO Steve Ballmer gives his presentation at the launch of Microsoft Windows 8.