I've allowed all the ads on websites since I went online. They have to be profitable. The last few months the ads have been shutting down my desktop. I'm looking for opinions on freeware adblockers. I don't mind some ads, but the pop-unders that eat RAM need to stop.

You can use AdBlock Plus extension on Google Chrome and Mozilla Firefox. It's good, and it will not show any of the ads on the page unless you deactivate it.

The best one to day is uBlock Origin (https://www.ublock.org/). They have add-ons/extensions for all major browsers.