To install Windows Update on computers running Windows 8, do the following.
1. Press the Windows button to open the Start Menu. In the start menu begin typing 'update', and you should see an option called Windows Update appear somewhere in the list that shows up on the right hand side of the screen.
2. Select the Windows Update option from the previous screen.
3. The following window will appear.
Select Check for Updates to get Windows to search for any available updates.
Click where it says how many important or optional updates are available to install to select which updates you actually want to install on the computer.
When you click where it says how many important/optional updates are available to install the following Window will appear for you to select updates in:
In this window on the left hand side you can select 'Important' to display updates which Windows deems as being essential or you can select 'Optional' to see updates which Windows deems less important.
You can check the checkbox beside 'Name' at the top of the page to mass select all updates or you can check or uncheck updates on an individual basis by using the checkbox beside a particular update.
Once you have selected the updates you want to install press the Install Updates to actually install them.
Once the updates are installed please restart the computer. Windows needs a restart in order to completely finish installing certain updates, and may take a long time once restarted to fully reboot.
Once the computer reboots, check for updates again, as sometimes after one batch of updates is completed Windows will find more than you need or are available for your computer.