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Many websites try to create operating revenue through ads in pop-up windows. This, however, sounds like a pop under.

Why is that when I go to some websites and look around and then when I leave and go to another website, the last site opens up another tab by itself and starts to load again and before I can close that one out, another tab opens up? This happens all the time from a number of different sites. How can I stop this from happening?

In this excerpt from Answercast #26, I discuss the way that pop-up and pop-under windows work and a few settings to try and stop them.

New tabs suddenly appearing

What it sounds like to me is you're experiencing what are called "pop-unders." These are (in a non-tabbed environment) windows that a website will attempt to open up as you exit... underneath your browser.

In other words, you wouldn't really see them until you've closed your browser for some other reason. I see this frequently with a particular advertising system that is used by some of the sites that I visit. I will move or close my browser window and amazingly, there's this advertisement underneath that I never saw.

In your case, it sounds like the ads are being generated in separate tabs; which I'm sure is a setting somewhere in your browser that says to open new windows in tabs instead.

Bottom line is that these are pop-unders: a form of pop-up windows. Make sure your browser's pop-up blocker is enabled.

Blocking pop-ups

Now, I will tell you that not all browser's pop-up blockers can block all pop-ups.

It's unfortunate. There's this constant battle between the people using pop-up technology and the browsers who are trying to block pop-up windows.

In a case like you're describing, you are getting new browser windows in tabs that the browser should hopefully be able to block.

  • Make sure that the pop-up blocking options in your browser are turned on.

If they are and you still end up with these pop-ups, you might consider (briefly at least) trying one of the other browsers (any of the big three: Internet Explorer, Firefox, or Chrome) as options to see if they are more able to block these pop-up or pop-under windows.

Or live with it

If not, so far I'm still living with it.

It doesn't happen very often for me. It really depends on what sites you visit. Certainly one or two sites that I rely on, themselves rely on this as a revenue generator – a way to make money; a way to keep their site up.

So, I just sort of tolerate it. I get a little annoyed, but I tolerate it and understand that it's a technique that they're using to stay alive.

Article C5463 - June 13, 2012 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

June 13, 2012 7:46 PM

I tried to add the domain of a pop-under ad I get annoyingly often to the Hosts file. But even though the read-only is turned off, I'm still unable to save the Host file. But I'm pretty sure that once I can, it should be able block those annoying ads.

You probably need to run your text editing program "as" administrator, as outlined here: Why does my computer say I need to be administrator, when I am?
Ken B
June 14, 2012 6:47 AM

@Bob -- Newer versions of Windows protect many of the system files, beyond a simple "read only" attribute. You need to use "run as administrator" (yes, even from an "administrator" account) in order to edit the hosts file. Right-click the icon for whatever program you're using, or type "cmd" into the "start" menu, and right-click the "cmd.exe" entry, and then select "run as administrator".

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