Have you tried a different browser?

 I had something on my machine once that had attached itself to Internet Explorer that was doing something very similar to what you are saying.

Are you sure you did not pick up a virus or some type of malware from another site?  Check your computer with the latest update of your anti-virus program and one of the anti-malware programs like this:

https://www.malwarebytes.org/

Thanks MI 2 AZ, I ran your suggested malware program.  Guess what, I logged on this site and have no more of those popups....I picked up something from somewhere.  Thanks again.

You're welcome.  Glad you got your problem solved.