redirect to other sites

A lot of times when I am on a site like youtube I will click on a video or just click anything I will be redirected to another page. It will be an advertisement about a product. It will also have a pop-up ads a lot of times. Very aggravating! I thought the firewall would block it but no. I have run full scans and have run grime fighter. Grime fighter has found things but it doesn’t fix the problem.

https://forum.avast.com/index.php?topic=53253.0