Thirty-one years after MS-DOS debuted on an IBM computer, Microsoft has unveiled the next incarnation of its operating system. Windows 8 is designed to work as well on a desktop, laptop or netbook as on a tablet or smartphone. That means touchscreens and a new way of interacting with a PC, but the question is whether this new unified interface is too ambitious and confusing for regular office workers. Where to start? We mean that literally, because Windows 8 lacks the familiar Start button in the lower left-hand corner. Here's another shock: Windows 8 dumps the idea of browsing via windows. It now uses a vibrant and colourful home screen called Metro which comprises square and rectangular tiles for photos, software, documents and apps. It's called up by pressing the hitherto useless Windows button on your keyboard. In reality the apps, which can be downloaded from a central marketplace, are nothing special, though we did download and use Evernote, WordPress and Photovault. The built-in instant messaging app - complete with Facebook integration - also proved a major distraction. Metro is good at navigating a computer. Each tile shows dynamic information. The photos tile shows your images on a carousel. Metro isn't just one screen, and can be zoomed in and out as well as searched left and right, and customised in terms of size and content. This flexibility has clearly been designed for fingers, with various swipes and gestures bringing task bars in from the sides of the screen. It is still possible to use a mouse and keyboard shortcuts to navigate Metro, but the use of the full-screen grid doesn't make much sense unless you can move to each tile quickly. There's scepticism about whether Microsoft has the clout to take on its customers' conservative instincts when it comes to daily computing tasks. Some say controlling a desktop computer purely by touch can't be done. Even Apple hasn't tried it on its iMacs despite the popularity of the iPad. But Windows dominates largely because it's designed to work on almost any hardware. Microsoft is certainly reaching for the clouds, in more ways than one. Windows 8 puts everything in the cloud, with all users given personal storage via a free service called SkyDrive. Storing an individual's settings, applications, files, photos and even an avatar, it's possible to log on to any PC in the world that uses Windows 8 and work as you would on your desktop computer. It all revolves around the use of a single Windows live ID that Microsoft is hoping we will all be willing to upgrade or replace. Integration is promised between computers running Windows 8 and other Windows-loaded gadgets, such as Microsoft's Xbox 360 games console. The Xbox Live hub in Windows 8 even allows its users to launch Xbox 360 games from a PC and can also stream video to an Xbox 360 for watching on a TV. There isn't a way to stream audio just yet, but Microsoft is clearly starting to position Windows 8 and Xbox to compete against similar video streaming features in Apple TV and the iPhone/iPad. Despite Apple's success with its interactive gadgets, Microsoft is still dominant in the world of computing, accounting for about 85 per cent of operating systems. But there is no guarantee that Windows 8 will be a success. Its predecessors - Windows 7 (2009) or Windows Vista (2006) - were not very popular, which might explain why 2001's Windows XP was still running on 38.5 per cent of the world's Windows computers as of October last year. Windows 8 will have to be something really special to tempt the silent majority of PC users to upgrade. If it does so, it will probably be through the back door. As well as pre-installing it on desktop and laptops, Microsoft is planning a huge ecosystem of devices that could include your next phone and tablet - unless you go for an iPad, of course. Microsoft is hoping that the unified experience will be irresistible. The tablet-friendly touchscreen design shows us what Microsoft is really aiming for. Its use on tablet computers will depend on the manufacturers, though Nokia has recently confirmed its intention to produce a Windows 8 tablet. Instantly familiar to anyone who's used a Windows Phone or Xbox 360 recently, the Metro user interface is key in this fresh and exciting mobile-friendly operating system, but it's the promised 'ecosystem' of gadgets that could really push Windows 8 into all our lives. We're in for a touchy-feely future - and not a Window in sight.