It sounds like you have a third party program that has taken over your search engine, home page, and/or the default new tab page. Fortunately, this can be remedied easily:

1. Click the menu button and choose Add-ons.
2. In the Add-ons Manager tab, select the Extensions panel.
3. Select the toolbar you wish to remove.
4. Click the Remove button.
5. Click "Restart now" if it pops up. Your tabs will be saved and restored after the restart.

After Firefox restarts, install the Search Reset Tool. This will remove the rest of the traces of this program from your Firefox.

For further information, please read Remove a toolbar that has taken over your Firefox search or home page.

If the above doesn't work, please see the article How to fix preferences that won't save as you may have third party software that prevents your preferences from being changed. You can also right click on your Firefox shortcut and select Properties, if the target line under the Shortcut tab includes a link after "firefox.exe" then that is the culprit.

Did this fix the problem? Please let us know!

Bookmark and use this; Download the Mozilla Search Reset {web link} This add-on is very simple: on installation, it backs up and then resets your search preferences and home page to their default values, and then uninstalls itself. This affects the search bar, URL bar searches, and the home page.

Settings Guard for Firefox 0.5 No Restart by Jorge Villalobos Settings Guard for Firefox {web link} Detects and resets changes to settings that are frequently done by add-ons and application installers.