Your computer most likely had McAfee on it at some point and was removed incorrectly.  I will not tell you how to remove it as you need to do it in a specific order or else you end up with the problem you're having.  A quick google search for "how to remove McAfee Popups" will give you numerous articles and offer multiple solutions.  One of them is to use the McAfee Consumer Products Removal Tool.  If that doesn't work you might try MalwareBytes free version.