Window 8.1 Update 1 makes it easier to use the operating system on your desktop PC or laptop. You can update your Windows 8.1 (KB2919355) through Windows Update. However, if you do not see the update or you have Windows Update turned off, here is how to update it manually. First of all, make sure that you have installed the servicing stack update (KB2919442) on you Windows RT 8.1 or Windows 8.1. If not, download the KB2919442 update and install it. Then download the KB2919355 update from here (x86 / x64) and install it. Finally restart your PC. If you have successfully installed the update, your desktop PC should restart to desktop directly. You should also see a new Power Button and search icon on the top right corner of the Start Screen.
