Sorry that you have that issue, but since it affects all your browsers it isn't a Firefox support issue. Chances are that anything we post here to try to help you is just going to be something you have already tried.

My suggestion is to ask for help in one or more of these forums for specialized malware removal help:
http://www.spywarewarrior.com/index.php
http://www.spywareinfoforum.com/
http://bleepingcomputer.com

You can also check if there is a user.js file in the profile folder to initialize some prefs on each start of Firefox. You can use this button to go to the Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

Note that Windows hides some file extensions by default.
Among them are .html and .ini and .js and .txt, so you may only see a name without file extension.
You can see the real file extension (type) if you open the Properties of the file via the right-click context menu.

The user.js file is only present if you or other software has created it, so normally it wouldn't be there. You should check its content with a plain text editor if you didn't create this file yourself.

The user.js file is read each time you start Firefox and initializes preferences to the value specified in this file, so preferences set via user.js can only be changed temporarily for the current session.

See also:

• http://kb.mozillazine.org/Preferences_not_saved

Browser Hijacker like redirect virusattack on the privacy of critical data stored in the computer and send them for commercial or evil purposes to cyber hackers. On your Mozilla Firefox browser type about:config in the address bar and hit Enter. It will display the list the name of preferences that can be changed for safe and better browsing. After this in the search box, search for preference name keyword.URL and click on the Modify the parameters leave it blank or write something other than what is written. Then search for browser.search.defaultenginename and change it to your favorite search engine as default. After this look for browser.search.selectEngine and reset it to something else others than what is already set. Then search for browser.newtab.URL and modify it to about:newtab, it will make you open new tab which appears blank. After this restart the computer it will be very helpful and will eliminate the browser hijacker. See more :

I ran into a similar problem. But I took a proactive approach. Follow these steps (as I did - with success):

1) If you have either uTorrent or BitTorrent installed on your system, uninstall them. They've both partnered with "Conduit" search.

2) Check your add-ons, plugins, and extensions to see if there is a torrent-utility related add-on/plugin/extension installed. If so, remove them ... or at the very least, disable them. The same applies if you see any Conduit add-on/plugin/extension. Then, close Firefox altogether.

3) In Windows "Accessories" programs, click on "Command Prompt" and make sure you're at the "C:\" prompt.

4) Type in "dir/s *ondui*" and hit ENTER.

5) Keeping your Command Prompt window open, open My Computer. Using the file/directory locations shown in the Command Prompt window, navigate to them in My Computer and delete any file or directory with the word "Conduit" in it. Some will require Administrative Privileges to do this.

6) Reboot your computer, open up Firefox, and type "about:config" in the address window, hitting ENTER. Type "Conduit" into the search bar and press the "reset" buttons on everything that shows up.

7) Close and restart Firefox. If this is a Conduit infection (like mine was), it will be gone.

Good luck,

J. Alec West

P.S. Note that my fix shown above was applied to my Windows 7 system running Firefox 25.

One other note. The Conduit bug can affect "all" browsers. So if you are infected with it, the file/directory deletions should remove the issue from your computer as a whole.

this generally happen when you download any software and while you download that softwrae along with that software such toolbar already ticked marked in small boxes also gets installed. It is called browser hijacker-it has the capability of changing your homepage, you can see added toolbar to your web browser and you can also see that you defult serch engine has been changed. Such hijacker also keep the records of your web history.

Browser Hijackers are malicious programs that are like web-browser plug-ins in Firefox that modifies the setting of the in order to change default home or search engine page and redirects your search to undesirable Internet sites. These viruses are designed for promoting their search engines, homepage, or other services as well as display ads. It even collects all the information about your web browsing habits and suggests services or advertisements related to that. Browser home page and default search engine are changed to the site it promotes. To eliminate this viruses from your Firefox you need to open the Firefox and type about:config in the URL box. Then there is no need worry about the warning window that appears just click on “I’ll be careful, I promise!” button and continue. Here you will see Firefox web configuration settings. Types in i.74055djs.info in the search box after this press enter. If you will see the item containing the malicious code, right click on it and then click reset. At last close the Firefox and open it again the problem will be solved. See more :

BROWSER HIJACKER alters the search and error page of a definite browser and redirects the user to its own page. The system users are redirected to pages that they hardly have any intentions of visiting. These are created purposely for marketing, commercial and publicity purposes. So, in order to get rid of browser hijacking you need to use spyware remover tool which is able to detect the file and prevents your PC from harmful browser hijacker effects. For more: