Sorry, more detail: I'm using Firefox 34.0.5 on a Mac with Yosemite operating system.

Now Firefox is substituting Amazon rather than Yahoo. It continues to ignore my preference for Google.

Please help... thank you.

I'm having the same problem. Whenever I turn my computer on, Yahoo has become the default search engine. I have uninstalled yahoo at least five times now, and it keeps coming back. This is quite bothersome, and none of the fixes in other responses seem appropriate to solving this problem. I can't even find an option for setting the default search engine; going directly into "about:preferences" is fruitless, the "manage search engines" menu has no default option...

Bothersome.

Firefox 34 brought a new Search Bar - read about how it works. https://support.mozilla.org/en-US/kb/search-bar-add-change-manage-search-engines-firefox

the-edmeister said

Firefox 34 brought a new Search Bar - read about how it works. https://support.mozilla.org/en-US/kb/search-bar-add-change-manage-search-engines-firefox

I've read that before, and it wasn't helpful the first time, either. For starters, that search bar looks nothing, nothing like the search bar I have. I have included a picture of my current search bar to illustrate. The search bar I have gives no choice for default, or for a way to specifically prevent yahoo from re-f*ing-installing itself, and the page you linked offers no additional insight.

I do not have version 34. I have version 35.0.1

Considering that you posted in a thread that was started about Firefox 34.0.5 by a user running MacOSX - it was assumed that you were also using Firefox 34, seeing that you didn't specify otherwise. No need to be snotty over that fact that I don't have a crystal ball to know which Firefox version that you have installed or what you may have modified.

If you are seeing the Search Engine name in the Search Bar with a Firefox 34 or later version, as that screenshot shows, you are not using the "default" new Search Bar feature - you probably disabled the showOneOffButtons preference or have an extension that disabled it. That disables the new "search features" that came with Firefox 34+ versions. Doesn't work any different than it did for many years, up to that change.

There is no "default" and if a Yahoo search engine keeps getting re-installed after you remove it, you must have some Malware on that PC which keeps reinstalling the Yahoo search engine.