if your manual changes don't 'stick' after a restart of the browser, please look out for any suspicious extensions (like 3rd-party-toolbars or things you have not installed intentionally) presently installed under firefox/tools > addons > extensions or the programs section of the windows control panel and remove those entries.

in case this doesn't solve the issue please try this: go to firefox > help > troubleshooting information > profile folder - "show folder", then a new window will open up. in this window look out for a file named user.js (it might be used to overwrite your custom settings). in case it is present, delete or rename this file and restart firefox afterwards.

Remove a toolbar that has taken over your Firefox search or home page

How to fix preferences that won't save

What is your home page?

Try to reset some preferences to the default with the SearchReset extension:

• https://addons.mozilla.org/firefox/addon/searchreset/

Note that the SearchReset extension only runs once and then uninstalls automatically, so it won't show on the "Firefox > Add-ons" page (about:addons).

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.