The much awaited final version of the free Microsoft Windows 8.1 update is now available for download, If your PC is currently running Windows 8 (or Windows RT) all you need to do is to open the "Windows Store" and you’ll see this free update prominently featured on the home page. If not, you must get the KB 2871389 update (which should be already downloaded and installed if using automatic updates) and install it manually and check again.

As expected the first preview of Windows 8.1 is out now for public download. To be released as a free update to Windows 8 later this year, this pre-release version is now available for downloading to early adopters.

Microsoft Windows 8.1 Preview is available as a free update from the Windows Store, as well as bootable ISO images. Users already running Windows 8 and updating via Windows Store need no extra serial number or registration, for new users installing from the ISO image are able to get this preview build for free using officially provided Windows 8.1 registration product key: NTTX3-RV7VB-T7X7F-WQYYY-9Y92F.

Microsoft says Windows 8.1 offers improved balance between the classic desktop UI and the new tile based “Modern” UI which is more suited for touch-screen usage. Apart from the return of the Start button and the much wanted boot to desktop option the new update features more personalization options, more apps, new "Search Heros" integrated web-searching, new Store, Extensive SkyDrive integration, 3D printing support, Miracast streaming and much more.