NEW YORK (AP) -- Microsoft is kicking off a campaign for its newest operating system, Windows 8, at a five-hour event at New York's Pier 57. Designed to run on both PCs and tablet computers, Windows 8 heralds the biggest change to the industry's dominant operating system in at least 17 years.
Windows 8 attempts to bridge the gap between personal computers and fast-growing tablets with its touch-enabled interface. The launch event comes amid a slew of other tablet offerings ahead of the holidays. Apple Inc. unveiled its iPad Mini with a 7.9-inch screen on Tuesday. Amazon.com Inc. and Barnes & Noble Inc., makers of the 7-inch Kindle Fire and Nook Tablet, are coming out with larger versions next month.
The Windows event in New York also heralds the launch of the software company's Surface tablet, its first venture into making computer devices. The device goes on sale Friday, as will computers and other tablets running Windows 8. Wedge Partners analyst Kirk Adams expects Microsoft to trail its rivals in fourth-quarter tablet sales.
One factor that might dampen enthusiasm for the Surface is its price -- $599 with its touch keyboard cover -- and its availability for purchase only from a limited number of Microsoft stores and online, Adams said. He said consumers may be reluctant to buy the device until they can try it in person.
Meanwhile, most analysts believe companies and governments will hold off on upgrading to Windows 8 for at least another year. About half of business users still haven't upgraded to Windows 7 from Windows XP, which came out in 2001.
XP also marked the last time Microsoft had a huge launch campaign for Windows. Microsoft also came to New York then, holding an event at a Times Square hotel. Releases of Windows Vista and 7 since then were more subdued.
Here's a running account of the Windows 8 event, presented in reverse chronological order. All times are EDT.
Presenters include Microsoft CEO Steve Ballmer; Windows chief Steven Sinofsky; Julie Larson-Green, the executive in charge of Windows Program Management; and Michael Angiulo, who heads the Windows Client and Ecosystem Team.
There have been few surprises, as Microsoft announced the release date and made preview versions available long ago. Microsoft's stock climbed 3 cents to $27.93 in midday trading. Trading volume was low, less than half of the average.
Larson-Green and Angiulo appeared on stage to demonstrate a Windows 8 machine upgraded with Windows 7 devices.
Microsoft announced the grand opening of its Windows online store, modeled after Apple's iTunes store. It will sell apps and content for Windows machines.
The store will be open in 231 markets around the world.
There are plenty of third-party apps available for iPads, iPhones and devices running Google's Android system. Sinofsky acknowledged that Microsoft's app store will likely be slim at first.
"We know some people might count apps and look for their favorite apps," he said. Hinting at more to come, he added, "We see today as a grand opening."
He said there are hundreds of apps added every day, in 109 languages. He said the Windows store has more apps than any other app store had at its opening.
Sinofsky said there have been 1,000 PCs certified for Windows 8, with the cheapest costing about $300. There will also be new models of slim, lightweight laptops called ultrabooks.
He reiterated that Windows 8 is designed to work equally well with touch-screen computers and those using keyboard and mouse commands.
Sinofsky opened by talking about past versions of Windows. He noted that the current version, Windows 7, came out three years ago this week. He said 670 million Windows 7 licenses have been sold since then.
He said that in creating Windows 8, "We shunned the incremental. We boldly reimagined Windows." He said there have been 16 million installations of preview versions of Windows 8.
The software will go on sale at midnight local time around the world.
Sinofsky appears on stage, which is flanked by 21 Windows 8 devices, ranging from tablet computers to "all-in-one" PCs, which are desktop computers with a built-in screen.
"Windows 8 is a major milestone in the evolution and revolution of computing," Sinofsky declares.