If you are using Internet Explorer to browse the internet, please make sure you are using version 11.
Go to Help -> About, or maybe the little gear icon and About to check the version.
Security patches are only going out on version 11 from now on. If you use an older version of the browser, it will not be updated. That means any new exploits will be forever exploitable on your machine.
Better yet, move to a different browser. We recommend Firefox, but Google Chrome is a popular alternative.