Hi Frank, we need more information on your situation. Is the problem that you want to ADD an ad blocker? Check out some available add-ons: https://addons.mozilla.org/firefox/search/?q=ad%20block&sort=users Is the problem that a website is insisting you TURN OFF your ad blocker? Firefox does not have a built-in ad blocker, but some ads are blocked incidentally by the Tracking Protection feature, which blocks tracking scripts. Blocking tracking scripts can trigger the site to accuse you of using an ad blocker. Or maybe you also have an ad blocking add-on.

More information about Enhanced Tracking Protection. *https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop *https://support.mozilla.org/en-US/kb/total-cookie-protection-and-website-breakage-faq *https://support.mozilla.org/en-US/kb/trackers-and-scripts-firefox-blocks-enhanced-track