I use Firefox, and have just downloaded the AdBlocker Plus add-in that you recommended to me PatriceJ. So far, no further pop-ups this afternoon. I haven't had the back arrow problem.
Belfrybat, I did have the problem with the slow strokes & when I looked up to the address bar, it had changed to autopartswarehousei.com so I closed out a few hours ago, and am now typing with no problems.