Do you have an Ask toolbar installed? Try to remove them via Software in the Control Panel. Use some adware/spyware scanner to find and remove them. Try to set Google als default search engine.

Toolbars and other crap are mostly included as promotion software to make or distribute the main software cheaper when installing this main software and when you forgot to uncheck its checkbox.

I had Ask Toolbar and uninstalled it. Restarted computer and tried Firefox again. Ask again came up. This happened originally when Firefox "updated" itself.

Once you have removed the add-on, you can try to reset the various search features of Firefox as well as your home page, if necessary.

For searches, try: https://addons.mozilla.org/en-US/firefox/addon/searchreset/

If there is a problem with searching via the default about:home page then try to reset the search engine used on the about:home page.

Reset the browser.startup.homepage_override.mstone pref via the right-click context menu to the default on the about:config page and close and restart Firefox to restore the about:home page to its default.

• http://kb.mozillazine.org/about:config

1. Open the about:config page via the location bar
2. Type in the Filter bar: mstone
3. Right-click the browser.startup.homepage_override.mstone line and select: Reset
4. Close and restart Firefox

If this didn't help then delete the delete the chromeappsstore.sqlite file in the Firefox Profile Folder and repeat the above.