Microsoft has released the consumer preview version of its Windows 8 operating system, which is expected to on general sale in Q4 this year.
The announcement was made by Microsoft Windows president Steven Sinofsky today at the Mobile World Congress event in Barcelona.
The operating system, which is designed to run on tablet devices, and desktops and laptops, is a significant departure from previous Windows iterations, Sinofsky explained.
"With Windows 8, we reimagined the different ways people interact with their PC and how to make everything feel like a natural extension of the device, whether using a Windows 8 tablet, laptop or all-in-one," he said.
It features a new tile-based design known as the Metro interface, and is optimised for touch-screens, though it will also work with keyboard and mouse.
This release also marks the opening of the beta version of the Windows Store, from which a variety of free apps from both Microsoft itself and third-party developers will be available.
Microsoft said that the store will recommend apps for users, and make them available across multiple devices.
"The Windows Store will offer personalised recommendations, and Windows 8 gives users the ability to take their apps and settings with them across multiple PCs, making it easy to discover and try new apps while offering developers the greatest opportunity of any platform," it said,
The latest version of Windows 8 provides access to SkyDrive, a Microsoft cloud storage offering, and enables email, calendar and contact data to be stored in the cloud.
This will also synchronise with Windows Phone devices.
The consumer preview release, which replaces the earlier developer release made available last year, can be downloaded directly from Microsoft.
Richard Edwards, principal analyst at research firm Ovum, explained that the reception of Windows 8 by consumers and businesses will have a significant impact on Microsoft, and its senior executives.
"If it fails to deliver the kind of experience that investors were expecting then this will be significant in the long term. Microsoft is affluent enough to survive in the short term, but the failure of Windows 8 could lead to the early retirement of some senior management.
"One could not imagine [CEO] Steve Ballmer receiving full backing from shareholders if Windows 8 turned out to be a flop like Vista."