Gone is the Start Menu. Gone is the Desktop. Instead, applications, widgets and social network updates appear in the form of a mosaic of tiles.
Everything is touch-friendly, as you swipe across screens to access more tiles and more tiles.
This is the new version of Windows, and it is almost ready for prime-time, with Microsoft preparing Windows 8 for launch in October.
Windows fans may lament their loss, but Microsoft has seen the future, and it is all about touch.
Microsoft officially announced the time-frame for Windows 8's mass-market release at a company conference in Toronto.
New versions of Windows typically come out every three years, but this update is the most widely anticipated overhaul of the software since 1995.
Microsoft, based in Redmond, Washington, has designed the operating system so it can run on personal computers or touch-based tablet computers.
Desktop aficionados may lament the new focus on touch - and wonder how it will work on older, non-touchscreen computers.
Critics may also wonder whether touch is any kind of replacement for keyboard and mouse in terms of day-to-day productivity.
Luckily those who miss the old approach will still find their Desktop accessible. But now it is more like a program, in the same way Office or Photoshop are programs.
The company is also putting a special price on its next version of Windows - offering upgrades to the operating system for just $40.
The offer, which translates to about £25 in the UK, will run until next January and applies to the previous versions of Windows - XP, Vista, and Windows 7.
Microsoft has not yet confirmed the price in the UK yet, but the company is likely to price the upgrade at between £25 and £40.
Microsoft will also throw Media Centre, which allows you to browse picture, music and video files from a distance, in for free.
Microsoft will be anxious to get the latest Windows on to as many desktops as possible, following the rising popularity of Android and Apple tablets, and Google and Apple - as well as other companies - encroaching in on the Microsoft-heavy segment of the PC market.
Windows 8 will be quite an evolution. The core Windows concept has changed little in more than 20 years, but for the first time, Microsoft is dramatically overhauling the interface, making it touch-friendly.
The Start Menu - and the desktop - have both gone, to be replaced with the Metro interface, which uses 'Live Tiles' for updates and for programs, in a manner similar to Windows Phone 7, and the upcoming Microsoft Surface tablet.
Those upgrading from Windows 7 will be able to keep all their settings, programs and files, while the older operating systems have some caveats, such as the inability to carry programs over from Vista, and settings over from XP.
Microsoft announced the moves on the company blog.
A spokesman said: 'We believe that your upgrade experience in Windows 8 will be a breeze by offering a faster experience, a single upgrade path, and compatibility from prior versions of Windows.
'We’ve continued to listen to our customers and have expanded the ability to download to over 100 countries and 37 languages.
'We have simplified the Windows upgrade experience with the Windows 8 Upgrade Assistant which supports you during your upgrade with everything from selecting your language to pausing your download to built-in compatibility checks - it’s seamless. And if you’re an enthusiast you will have the flexibility to download and control how you upgrade.
'If you prefer to shop at a local store, a packaged DVD version of the upgrade to Windows 8 Pro will be available for $69.99 during this promotion.
'This upgrade promotion for Windows 8 Pro both online and at retail runs through January 31st, 2013'.
