pop up for website to open content using adobe flash player pops up continuously, on all websites

All of a sudden today I started getting popups -- one after another to the point that I can hardly browse-- saying the website is trying to open content using adobe flash player. I click to Not allow and move on. I don't know if it's just a video or something harmful so I keep denying it. It is happening on All websites without me clicking on anything. It doesn't seem to be related to anything that I have done, I've done all the upgrades for programs and security, and my pc is only a couple of weeks old.

any suggestions on what exactly is causing this or what I can do to fix it? I don't want to just bandaid the issue and I don't want to cause any malfunctions on my computer.