As promised earlier last week, Microsoft has released the first major Update to Windows 8.1 and is now available via Windows Update. PC users who’re running Windows 8.1 should now be able to see and install this mandatory update for Windows 8.1. One can also download Windows 8.1 ISO file from MSDN. Windows 8.1 Update is a free, mandatory update with a number of enhancements and fixes. Number of users who’re eagerly waiting for the official release of this wildly leaked update are now complaining that the Update isn’t appearing in Windows Update. Update for Windows 8.1 will appear as KB2919355. If this Update isn’t appearing in Windows Update, it could be because one of the following reasons: This Update is only for Windows 8.1: This brand new update is only for PCs running Windows 8.1. That is, if you’re running Windows 8, you need to first upgrade your Windows 8 installation to Windows 8.1 and then install pre-requisite update (KB2919442) in order to see KB2919355 in Windows Update. Turn on automatic updates: Open Windows Update settings, and here, make sure that Install updates automatically option is selected. It’s not available to everyone right now: Though Windows 8.1 Update has officially been released, because it’s a rolling update, it might not be available to everyone right away and you might need to wait for a day to see the update. Can’t wait? Install the update manually: If you can’t wait to upgrade your PC to Windows 8.1 Update and want to do the same right away, you can manually download and install the Update. Installing the Update is extremely easy. Simply follow the instructions in our how to install Windows 8.1 Update right now guide or Windows 8.1 Update direct download links to easily download and install the update. How do I know that my PC running Windows 8.1 Update? Simply switch to the Start screen, and if power and search buttons are appearing at the upper-right corner (next to the user account name), you’ve successfully upgraded your PC to Windows 8.1 Update. Good luck!