See http://kb.mozillazine.org/Location_Bar_search and http://kb.mozillazine.org/Keyword%2eURL (pref: keyword.URL)

See also What to do when searches take you to the wrong search website

Try http://apps.conduit.com/conduitengine/Uninstall/

It works on my windows XP.

I was successful in removing the conduit search engine but could not get the Google home page. For those who are interested -- open up the firefox browser, find the small white triangle on top on the rt. side, click on the tab, rt click on the tab- conduit.com in the drop down list, click on the close tab. you will be relieved of the irritating search window.

I followed the advice on this blog

http://thesietch.org/mysietch/keith/2010/12/08/how-to-remove-conduit-engine-search-from-firefox-3-x/

and now conduit.com is gone!

(fixed link -c )