Did you do a clean install of the current Firefox release and deleted the Firefox program folder to make sure that no remnants were leftover?

You can find the full version of the current Firefox 28.0 release in all languages and for all Operating Systems here:

• http://www.mozilla.org/en-US/firefox/all.html

Create a new profile to check if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

I ran through the folder deleting each and every piece of it item by item 1 at a time b-4 uninstalling firefox. 13 times I have tried now. I cant get into firefox to profile manage a new profile or delete the old one because yahoo has firefox completely dominated. I entered the official Mozilla website just as prescribed, and I get the same result every time. I guess I cant use firefox any longer. that is unfortunate for Mozilla. they should consider reevaluating the yahoo debacle. it will ultimately eliminate them as a viable browser in a very competitive marketplace...

Could you please take a screenshot of Firefox being dominated by Yahoo and post it here? I'm trying to see how much of the browser Yahoo has dominated or if another addon like the Yahoo toolbar is doing it.

Firefox from mozilla.org does not come with Yahoo though there is a Yahoo bundled version of Firefox from a Yahoo download page.

Chances are it got installed during some new application install or a application update.

Just a quick comment.

If anyone installs the standard Firefox desktop browser from the official Mozilla site the only Yahoo element is that it has a choice of several search engines. The default is usually being Google, and one of the other choices is Yahoo.

Other search engines may be easily added or the original ones removed. Firefox gives you opportunities to customise many aspects including search engine choice.

Problems where something else is dominating Firefox tend to be because an modifies browser has been downloaded, you or other software has added toolbars or you have a malware problem.

Note malware or potentially unwanted toolbars may affect other browsers on your computer not just Firefox.

thanks to everyone that tried to help with this yahoo hijacking problem. I took all of the recommendations to the task, however, none of it was successful. after nearly giving up on firefox after the 14th download I accidently discovered the cure. with the firefox logo on my taskbar I clicked on it to launch "yahoo" once again but raced into the topleft corner to click on the firefox tab b-4 it disappeared within micro seconds. it cant be done. but accidently I dragged yahoo down to reveal the firefox logo tab and was able to rightclick access to add-ons! success to disable yahoo toolbar, but that still doesn't eliminate yahoo dominance. in order to do that simply find firefox with bing on a website, download it, install it, and success. now I click on firefox logo on my taskbar and yahoo is longgone. it is 28.0 in all its glory with the horny fox humping the globe center screen. thx once again to all who tried to help. I hope this experience can help the next computer illiterate as I stumble towards literacy...

The moral here is: always get your Mozilla applications from Mozilla, not from some third party.