I have read and tried everything I have found online for this issue. Currently, I have found a fix, although I don't know how long that will last before I open my browser and yet again find Yahoo to be added back.

I uninstalled Firefox from my computer. Then I went to Internet Explorer and use that to reinstall Firefox. Then, I made sure that Yahoo wasn't in my search engines (just Google), and then made sure that Google was my homepage. Double checked that it wasn't listed in extensions/plugins, etc.

Currently, the scourge that is named Yahoo is gone. Hopefully it stays that way. However, Firefox has completely lost my son as a user since he got so tired of Yahoo a while a go that he has become a happy Chrome user. That is too bad, as he is an older een and instead of being a life-long Firefox user, he is anti-firefox.

I am unsure where this stupid Yahoo things has come from, as so many times I have removed it from his computer (and mine) only to find an update or whatever has put it back again and removed Google from being our home page. At least for today, Yahoo is gone, but if the past has taught me anything, it is just temporarily dormant, like some chicken pox virus that is just waiting there, lurking in the shadows, waiting to come out again in the form of shingles (aka Yahoo) to plague us once more. >:(

Hi Jenny, Firefox is designed to allow you to change your default search engine once and remember it permanently. One situation in which Firefox will reset your default search engine is if you use the Refresh feature.

In other threads, users who removed ALL of the search engines other than their default had problems keeping their default when Firefox updated. Instead, try just unchecking unwanted search engines to remove them from the search bar drop-down.

If it changes under other circumstances, the cause might be an extension, locked settings files, or external software.

To address those possibilities, here's my suggested procedure for tracking down and cleaning up bad add-ons and other hijackers. I know it seems long, but it's really not that bad.

(For Windows Vista, 7, 8, 8.1, 10; XP is somewhat different)

(1) Open the Windows Control Panel, Uninstall a Program. After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Be suspicious of everything you do not recognize/remember, as malware often uses important or innocent sounding names to discourage you from removing it. Take out as much trash as possible here.

(2) Open Firefox's Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons
• in the Windows "Run" dialog, type or paste
  firefox.exe "about:addons"

In the left column, click Plugins. Set nonessential and unrecognized plugins to "Never Activate".

In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions. All extensions are optional; none come with Firefox.

Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

Any improvement?

(3) You can search for remaining issues with the scanning/cleaning tools listed in our support article: Troubleshoot Firefox issues caused by malware. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case.