This is one annoyance that I have been extremely glad to fix on my computer. After updating Windows, you might get a little shield icon on the bottom right of your computer screen that pops up every once in a while and says that your computer may be at risk. You may not have a firewall enabled or updated virus scan software, but if these are things you have set up intentionally, then use this tip to disable the notifications:

On the left side of the Security Center Window, look for something that says "Change the way Security Center Alerts Me". Click this, and when the new window pops up, uncheck every single box if you do not wish to see the annoying notification message pop up ever again. If you need a reminder to go find anti-virus software, then you can leave that box checked until then.

Even if you have anti-virus software or a firewall enabled, the Security Center may not detect it and continue to pop up until you disable it as shown above.