The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

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.

afterwards install the search reset addon, it will revert the most common settings that got modified by adware back to the default ones: https://addons.mozilla.org/firefox/addon/searchreset/

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

See also:

• [/questions/934685] Firefox Homepage Hijacked by Claro-Search
• [/questions/933520] Whenever I click on plus tab on firefox browser, Isearch.claro page opens up.
• [/questions/934390] How do i get rid of Claro-Search taking over NEW TAB function?

• http://systemexplorer.net/file-database/file/browsemngr-dll
• http://botcrawl.com/how-to-remove-the-isearch-claro-browser-hijacker-virus-isearch-claro-search-com/