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.