Adblock Plus {web link} Blocks annoying video ads on YouTube, Facebook ads, banners and much more. Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).

Adblock Plus Pop-up Addon {web link} Adblock Plus Pop-up Addon extends the blocking functionality of Adblock Plus to those annoying pop-up windows that open on mouse clicks and other user actions.

Forum; Adblock Plus Homepage {web link}

Just In Case; You may have ad / mal-ware. Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.

Sorry my bad, I forgot to mention I already have Adblock Plus installed. The second link you posted (Adblock Plus Pop-up Addon) says add-on not found.

Anyway, blocking ads is not the issue, the core issue as I said, is that links still open in new windows instead of new tabs, even though I have the setting: (open new windows in tabs instead), checked. Plus I have the setting: (switch immediately to new tab/window), unchecked, so I should not be switched to a new tab/window, yet I do get switched pretty much 100% of the time.

Have you tried using the scanners I linked to?

Sometimes, a code is sent telling the browser to open a link in a special way.

Sounds like a Malware issue.

The setting for "Open new windows in a new tab instead" isn't going affect "pop-up" windows. And, with both Adblock Plus and the Adblock Plus Pop-up Addon installed you shouldn't be getting pop-ups from advertisements. That leaves Malware on your PC as the probable cause.

It's a fresh OS install, no malware at all.

As said, I have Adblock Plus, but not the Pop-up Addon, because the link posted above results in "No add-on found" and searching didn't find one by that name.

To explain exactly the best I can: - If I go to a site now, click on something within that site, say a link to another page or thread, that original tab will go to the link I clicked, but a separate Firefox window will open, some times it might be a new tab, but either way I will be immediately switched to it, which shouldn't happen.

I'm just trying to stop the auto switch to the new tab or window which shouldn't happen. And also stop these links, ads, pages and anything else opening new windows instead on new tabs like they should.

Please run the scanners. Malware has a way of sneeking in.

FredMcD - I appreciate what you are saying, but as I have already said, there is no malware on this setup, it's a fresh OS install and it's checked multiple times.

It's a little complicated because Firefox has different preferences to handle various subtly different things.

(1) Pop-ups that have "features" specified (e.g., height, width, toolbars to show and hide)

Firefox assumes these are dialogs related to the page you're viewing and shows them in new windows even if regular new windows are diverted to tabs. Sites might be using this to bypass the usual diversion to a new tab instead. To override that:

(A) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(B) In the search box above the list, type or paste newwin and pause while the list is filtered

(C) Double-click the browser.link.open_newwindow.restriction preference and change the value from 2 to 0 (that's a zero) and click OK

What do these values do?

• 2 = apply the regular setting to normal windows, but NOT to script windows with features (default)
• 1 = override the regular setting and always use new windows
• 0 = apply the regular setting to ALL new windows (even script windows)

(2) Firefox focuses windows diverted to a tab instead by switching to the new tab, regardless of the setting on the Options page

There's a separate setting. If you do not want the new tab focused:

(A) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(B) In the search box above the list, type or paste inback and pause while the list is filtered

(C) Double-click the browser.tabs.loadDivertedInBackground preference to switch the value from false to true

You can use this as a test page to see whether the settings changes work:

https://jeffersonscher.com/res/popit.html

The above probably doesn't cover everything because you may be dealing with Flash or another plugin and what it can do.

@jscher2000 -- Legend! Thank you very much for actually reading what I posted and for not just assuming it was my PC that was the issue. So far seems to have done the trick, exactly what I was looking for, thank you kindly for taking the time to help me. I try to learn and solve my own problems first before asking for help, but this had completely confused me.

Thanks again, much appreciated. Merry Christmas to you :)