Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac=<Command>)<Shift> A)

In the Add-ons Manager, on the left, select Extensions. Remove yahoo Anything. Now do the same in the computers Programs Folder.

Windows: Start > Control Panel > Uninstall Programs. Mac: Open the "Applications" folder. Linux: Check your user manual.

This doesn't answer the OP. "remove yahoo anything" implies that yahoo is there. This is called a "Fix" not "stop" it from happening. Yahoo is there (in your example) because Mozilla allowed it to manipulate fox. The question is how to prevent that from happening.

If the user did NOT switch to yahoo, the above "fix" would not exist, because yahoo would not be there.

this fix is all over the net. Can Mozilla make it so any changes from the original (sorta like a UAC) that the user is alerted first, and accept or deny. not ALLOW IT TO HAPPEN then have the user frantically search the net for a "fix".

Klyx said

With that said, lets ask it differently this time, why does mozilla allow other sites to arbitrarily, at a whim, allow a website make changes to someones browser? If someone sets their browser to a specific search engine, mozilla should not allow it to be changed by an outside source, other than the owner (the user in this case), at BEST maybe a warning system from fox itself asking for the change.

Websites cannot change your default search engine in Firefox without installing a local file of some kind, either a program that alters your settings or an add-on. If you have seen any site demonstrate how to hack the default search engine setting just by visiting a web page, please report the URL to Mozilla for urgent investigation.

Downloading a program and especially installing an add-on prompts the user to allow/disallow the installation, although the site may not be honest about the purpose and effect of the program, and Firefox can't deconstruct a program in real time and tell you in advance what it does.

The most common case seen on this forum is where a user downloaded some free software like "watch live sports anywhere" or "record any video" and it is bundled with a range of invasive software that either wasn't disclosed or you just didn't notice in the 10 pages of fine print you accepted. In fact, the installer may have been downloaded with any browser and affect all your browsers.

As for what programs you allow onto your system can do to Firefox, Firefox assumes you accepted them and lets them run if they meet current validation requirements and haven't been reported for blocking. There is not a ban on add-ons that affect searching. If you think there should be, you could raise that suggestion on the Add-ons forum here:

https://discourse.mozilla-community.org/c/add-ons

@jscher2000, thank you! That is probably the most through answer regarding this I have seen. [quote] Firefox assumes you accepted them and lets them run if they meet current validation requirements and haven't been reported for blocking./quote This is very interesting. Many people would love to see fox intervene on this aspect - the "auto approve" can get slippery.

I only mentioned this today, since I was still on my original search, when i went to yahoo, to check mail, didnt get that far before I was distracted, and did a quick search and it was in yahoo - nothing was installed, just the front page came up. I removed the offending search setting (which magically appeared - my searches are empty but the one that I use. so you can imagine my surprise when I see something in there I did not add)

First, if an extension mysteriously appears in a folder on your system that Firefox monitors, Firefox will display an approval page. You might have seen this for security software or other external programs that push add-ons to your browsers.

Second, what search setting appeared? The search settings page may not be as clear as it could be: the top section shows what search engine will be used for searches in the search bar, address bar, etc. The bottom section shows what icons will appear as alternate search sites on the drop-panel from the search bar. Removing Yahoo from the bottom section does not affect the top section, so it's critical not to overlook that first setting. Here's a recent thread with that exact issue: BLOCK YAHOO AND BING -- default search engine McAfee Secure Search uses Yahoo.

It’s very sad, but many of the software downloaders / installers will trick you into installing not only their program, but other programs as well. You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print. You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does. From now on, everyone needs to Use The Manual Option to put a stop to this.

Thanks for helpful answers! I've stumbled upon an issue with the search engine defaulting to yahoo. Went to my add-ons and found Search for Firefox add-on I never installed. I removed it, and now I'm reunited with Google.

I think this junk came with McAfee add-on I installed. But honestly, where was that warning when I installed McAfee? Shouldn't I know about more stuff added to my browser beforehand? This is frustrating. Preventive options don't exist, I guess.

Hi Lili_, recent versions of Firefox usually display a tab at startup when a new externally installed extension is detected, asking whether you want to activate it. If you want to see what that looks like for the extensions on your system, you can create a new profile (just for testing, don't remove your existing profile). See: Profile Manager - Create, remove or switch Firefox profiles.

That was very good work. Well done. Please flag your last post as Solved Problem so others will know.

It’s very sad, but many of the software downloaders / installers will trick you into installing not only their program, but other programs as well. You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print. You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does. From now on, everyone needs to Use The Manual Option to put a stop to this.

Lili_ said

I think this junk came with McAfee add-on I installed. But honestly, where was that warning when I installed McAfee? Shouldn't I know about more stuff added to my browser beforehand? This is frustrating. Preventive options don't exist, I guess.

IMO, free McAfee crap is a well known purveyor of PUP (potentially unwanted programs) / Malware. Many users "pickup" McAfee when they go to download Adobe Flash for Firefox - it is a pre-selected "Optional offer" that too many users don't take the time to de-select. Once the user approves the installation of Flash, anything else can be installed without any further approval being needed. That is the fault of Windows and Adobe by allowing multiple installers to piggyback on the initial program the user approves for installation. And once Windows is involved there is nothing that a program like Firefox can do; the operating system overrides anything that Firefox might want to prevent from getting onto the hard drive.