Unwanted web windows keep appearing

Hello Colin.
We're here to help.
On which web browser do you experience this issue? Please share a screenshot of the windows that you are referring to.

Since I explored varius websites and social things, a 3" window keeps appearing on my PC screen, leasing me to all sorts of offers.  How do I stop it?

Hello Colin.
We're here to help.
On which web browser do you experience this issue? Please share a screenshot of the windows that you are referring to.