Mary's laptop technician put in an ad blocker with her browser, and now she's being bothered to turn it off every time she visits Yahoo. Leo says a lot of websites now are seeking to get her to stop using the blocker in order to get paid by ads. So they want her to unblock them in order to see their ads. Chances are, that the browser has an extension. There should be a way to "white list" the yahoo page so that popup will stop occurring.
But since Mary is using Windows 8, she's got even more problems. She'd be better off with a Chromebook. A Windows laptop is far more complicated than most people need.