The Microsoft Windows 8 operating system is unveiled at a news conference… (Mario Tama, Getty Images )
Microsoft Corp. has rolled out Windows 8, the most radical overhaul of its computer operating system in nearly two decades.
With Windows 8, the Redmond, Wash., company is hoping to remain relevant in today's tech-savvy consumer market. The latest update includes a new interface called the Start Screen that is unlike anything seen before on a Windows operating system. The Start Screen was designed for tablets and touchscreen computers and features moving tiles similar to those on Windows Phone devices.
Windows 8 is geared not just for personal computers but for tablets, laptops and smartphones, much like the way Apple has designed its operating systems to work across different devices including Mac desktops, iPad tablets and iPhones.
Analyst Michael Gartenberg of research firm Gartner Inc. said Windows 8 may be the most important launch in Microsoft's history.
"This is the most major revision to Windows that we've seen probably since the first versions of Windows came out," he said. "There's definitely a lot at stake here."
Gartenberg said Microsoft needs to explain to consumers why the radical change is happening, why it's better and why they should relearn how to use an operating system they already know.
The company held a launch event Thursday at which it began to do that, but "now they have to take that message to the masses and reintroduce Microsoft as an ecosystem to the consumer in the digital age," he said.
Microsoft wants the new Start Screen interface to be the future of Windows. In the meantime, the software company will attempt to ease users into the new era by allowing them to also use Windows' familiar desktop interface.
"This is not a transition they can do overnight or even in one release," Gartenberg said. "It's clear that this new user interface is the future, but it would be too much to ask every business and consumer to suddenly break with the past."
Microsoft began selling Windows 8 online at midnight starting at $39.99. The new operating system will be on the shelves at retail stores Friday morning.
Windows President Steven Sinofsky said Thursday that more than 1,000 computer models have been certified for Windows 8 and that there will be some PCs running Windows 8 that will sell for less than $300. Sinofsky also said Windows 8 will work well with Windows 7 PCs, making them boot up faster and run more efficiently.
Microsoft also launched an online store for Windows 8 apps similar to Apple's App Store. Sinofsky said the Windows Store has more apps than any competing stores had when they launched.
Microsoft and Sinofsky also used Thursday's event to speak about Windows RT, a downsized version of Windows 8 that will be used mostly on tablet computers.
Windows RT uses an ARM processor, which is smaller, cheaper and uses less power than other computer chips. However, Windows RT can only run apps purchased from the Windows Store and it does not have the desktop view.
Microsoft's long-anticipated flagship tablet, the Surface, will begin selling Friday. It runs on Windows RT. A Surface tablet running the more robust Windows 8 operating software will launch later, the company said.