Details: Microsoft's Windows 8 event

• Microsoft has a lot riding on Windows 8
• Launch event in New York includes partners Hewlett-Package, Sony and more

NEW YORK — Microsoft and multiple PC partners including Hewlett-Packard and Sony have assembled here in New York at Pier 57 to officially launch the Windows 8 software upgrade, which goes on sale Friday.

The format: Microsoft execs speak for an hour, then it's hands on with desktops, laptops and the new Surface tablet.

The event has now concluded. Below are details from our live coverage:

12:13 p.m. And that's it. The event is over. Now we are being shepherded to hands on area.

12:12 p.m. ET: Dell, Acer, Samsung, Asus, Toshiba, Lenovo, Sony and HP are the PC partners showing off new Windows 8 computers here.

12:11 p.m. ET: Ballmer says 670 million PCs just waiting to be upgraded to Windows 8. Those are very large numbers.
He says analysts project sales of 400 million new PCs.

12:06 p.m. ET: Here are a few notes via Twitter from USA TODAY'S @edbaig: Microsoft says it is easy to uninstall a Windows Store app. No fragments of app left in registry. Sinofsky says Windows RT works out of box with 420m devices. The new Windows Store is available in 231 markets. (But Microsoft has a mere fraction of the apps in Apple's App Store.) Sinofsky says over 1000 PCs have been certified for Windows 8. Ultrabooks, mobile tablets, convertibles, multiple price points.

12:05 p.m. ET: With Windows 8, Microsoft aimed to marry PC and tablet work and play. "Flip, dock, convert, attach."

12:02 p.m. ET: Ballmer says - best PCs ever, the thinnest, lightest and fastest PCs ever created. Advanced tech pushes the boundaries of what a PC is: touchscreen, Ballmer says.

Noon ET: What you've seen and heard should leave no doubt that win 8 shatters perceptions of what a PC truly is. We've reimagined Windows and kicked off a new era for Microsoft and our customers.

11:58 a.m. another promo video on now. Steve Ballmer takes the stage.

11:55 a.m. : Lots of convertible laptops meet tablets. Computer on bottom with monitor that clicks off, and becomes a tablet. Lenovo, Dell and HP all have them.

11:54 a.m.Showing off apps, games, news apps, and how it's quick to download them. PCs that are thinner and with longer battery life, can also run the apps. Windows RT has Office built-in

11:48 a.m. ET: Wi-Fi reconnect is faster in new Windows 8. A Lenovo ThinkPad Tablet 2 has a stylus that lets you write on the screen.

11:45 a.m. ET: Microsoft managers are showing off the software. The Windows 8 interface is based on a tile system that lets you move and change the look of the screen with your fingers and a touchscreen interface.
Microsoft touted that boot-ups are faster, and the fun of using the tiles for navigation. For those who don't have a new Windows 8 computer----older Windows 7 computers can move the tiles around with trackpads.

Microsoft keeps saying the PCs shown at the event are "the best PCs ever." Really?

11:38 a.m.ET: Microsoft touts Windows RT, a new version of Windows for ARM based computers. Has better battery, includes Office 2013, can run apps in the new Windows App store, and works with 420 million devices.

11:36 a.m. ET: Like Apple's App Store? Now Microsoft has a Windows Store online. Can buy Windows 8 there for $39.99. New Microsoft Windows App store includes apps from Netflix, Vimeo, NBC News and FX.

Microsoft says Windows 7 was best-selling version of Windows operating system.670 million licenses.

11:25 a.m. ET: Microsoft says that 1 billion people use Windows and with Windows 8. "We're looking forward to the new billion." It was introduced 3 years ago this week. Windows 7 sold 670 million licenses to business and consumers.


11:20 a.m. ET: The event opens with an Apple-like promo video showing the software in use all over the world, with shots of people in China, India and other countries.
Microsoft executive Steven Sinofsky walks on stage. He wears a sweater over white t-shirt.