At the bottom left of your screen next to the Windows start flag, there is a search box in most cases that looks like this.
Select that search area with your mouse, and type in "Windows Update"
Select the item labeled "Check for updates", and when the next screen is displayed (pictured below) click on "Check for Updates" (it's circled in red below)
After clicking on Check for Updates, it's not necessary to watch it. Check on it periodically. When it's done getting ready it will ask to restart. The restart may take a long while to complete. However, if you start the process when you're done for the day and let it run, Windows will restart automatically in the middle of the night to finish the install.
After updates have successfully run, and a restart has been performed, do the process again around 30 minutes after the initial restart. It's possible that the updates you just installed require subsequent updates.