Hi Niki-, sorry to hear about this problem. Have you checked the suggestions in this support article:

Firefox hangs or is not responding - How to fix

Also, where did you get your "Ad Remover" extension? Try disabling that and using a well known free one such as uBlock Origin.

You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions.

Then you can manage extensions on the right side.

And you can install uBlock Origin from here: https://addons.mozilla.org/firefox/addon/ublock-origin/

Any improvement?

Thank you. I get very frustrated with this technology, which only seems to get worse. The ad-remover is a Norton Antivirus product and is the best $29 I've spent in a long time. Firefox was freezing before installing this.

I believe the problem is actually related to something stupid, an online Tetris game (palmantics.com). Freezing tends to occur after playing this (though not always). I just always think 30 year old game-ware shouldn't be a problem.

Niki- said

I believe the problem is actually related to something stupid, an online Tetris game (palmantics.com). Freezing tends to occur after playing this (though not always). I just always think 30 year old game-ware shouldn't be a problem.

That site uses Flash. Do the other problems seem related to the Flash plugin? Any pattern you can identify may be helpful.