If Firefox ignores your setting for the default search engine, or if it keeps switching, you probably have a bad add-on.

First, just to confirm, here is the article on changing your default search engine: Change your default search settings in Firefox.

Here's my suggested procedure for tracking down and cleaning up bad add-ons, hijackers, and ad injectors. I know it seems long, but it's not that bad.

(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. 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. Bear in mind that none of these came with Firefox, they are all optional.

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.

Success?

in the article on how to change your default search engine, it shows how to select your search engine, like google. However a new version of firefox was automaticly installed on my computer, and that option has disappeared. That drop down box is gone. Therefore I am not able to select a search engine. Silke

Firefox 41 should still have the same Options page and search section. Could you select and copy the following, then paste it into the address bar and press Enter to load it:

about:preferences#search

Does that load a page which matches the help article?

Try to delete the search.json file and possible search-metadata.json and search.sqlite files in the Firefox profile folder to reset the search engines to the default.

You can use this button to go to the current Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Firefox will rebuild the search.json file from the default built-in search engines that come with Firefox and the searchplugins folder in the Firefox profile folder.

Thank you for trying to help me. I am not very computer savvy, and do not feel comfortable executing the suggested tasks. Is it possible for you to download a better version of firefox where I can select my search engine? Thank you Silke

You can try to Refresh Firefox and create a new profile.

• https://support.mozilla.org/kb/reset-firefox-easily-fix-most-problems

When you Refresh/Reset Firefox then a new profile is created and some personal data (bookmarks, history, cookies, passwords, form data) is automatically imported. The current profile folder will be moved to an "Old Firefox Data" folder on the desktop. Installed extensions and other customizations (toolbars, prefs) that you have made are lost and need to be redone.

thank you for helping me refresh my firefox version, I now can choose my browser. Silke