Windows 8.1 Update(also known as KB 2919355) include improvements that make your favorite apps and settings easier to find and use, and provide more familiar mouse and keyboard options.
It might already be installed
If you’re running Windows 8.1 or Windows RT 8.1 and you get updates automatically, you don’t need to do anything: Windows Update will download and install the update for you within the next few weeks. It won’t interrupt what you’re doing except to tell you that you need to restart your PC to finish the installation.
To check if the update is already installed, go to the Start screen. If you see a Search button near your account name at the top of the Start screen, you already have the update.
After the update, the Search button appears on the Start screen.
Install the update manually
If you’re running Windows 8.1 or Windows RT 8.1 and you don’t have the update yet, you can manually check for and install the update by following these steps:
Make sure your PC is plugged in and connected to the Internet using a non-metered connection. Don’t disconnect, unplug, or turn off your PC while the update is being installed.
Swipe in from the right edge of the screen, tap Settings, and then tap Change PC settings.
(If you're using a mouse, point to the lower-right corner of the screen, move the mouse pointer up, click Settings, and then click Change PC settings.)
Tap or click Update and recovery, and then tap or click Windows Update.
Tap or click Check now.
If updates are found, tap or click View details.
In the list of updates, select the update containing KB 2919355, and then tap or click Install.
If you're prompted for an administrator password or confirmation, enter the password or provide confirmation.
After the installation is complete, restart your PC and sign in.
Note
If you don’t see KB 2919355 in the list of available updates, you might be missing one or more required updates. Follow the previous steps to check for updates, install all important updates, particularly KB 2919442, restart your PC, and then check for KB 2919355 again.
Microsoft recommends you install all updates in the following order to avoid issues. Always reboot when prompted (don't skip a requested reboot between updates, you'll cause big problems!)
KB2919442
KB2919355
KB2932046
KB2937592
KB2938439
KB2934018
These KBs must be installed in the following order: KB2919442, KB2919355, KB2932046, KB2937592, KB2938439, and KB2934018. KB2919442 is a prerequisite for Windows 8.1 Update and should be installed before attempting to install KB2919355!
