Dear bidouille,

so do you want to have a default search as Google.fr, and you want to delete toolbar and page named OMOGA? Have you downloaded it from official Firefox page?

Thanks, Wojtek

It could be the work of one of your add-ons, or even add / mal-ware. Look thru your add-ons list and make sure you know what each one is there for. Also, check the programs that are on your computer

Windows: Start > Control Panel > Uninstall Programs.

Go thru the list. If you find something that you don't know what it is, use a web search.

Troubleshoot Firefox Issues Caused By Malware {web link}

Firefox any version for any OS from mozilla.org and updates from them does not come bundled with any form of malware, viruses, and toolbars.

Firefox 31.0b4 from http://www.mozilla.org/en-US/firefox/beta/all/ is clean.

However there is a 31.0b5 http://download.cdn.mozilla.net/pub/mozilla.org/firefox/releases/31.0b5/win32/

You really should take a quick moment to tailor your clipboard postings to the OS the poster has Fred.