Web browsers have a search bar that allows users to trawl the web without navigating to the search engine's dedicated web page. In the case of Firefox 4, Google is the default search engine. However, it's easy to change this to a search engine that suits you. Here's how.
Open your Firefox browser, and then click the drop down menu in the search bar (located at the top-right of the browser).
From the drop down menu select another search engine (Firefox's suggestions include Bing and Yahoo). Alternatively, select Manage Search Engines.
Press Get More Search Engines and the Mozilla Add-ons search extensions page will be displayed. Scroll through the add-ons list to locate the search engine you want to use, then click the Add to Firefox button on the right-hand side.
The search engine will now be displayed in the drop down menu in the search bar. Alternatively, when visiting a website, if a Firefox add-on is available, the Google icon will take on a blue glow. Press the drop down menu and then click the Add 'xxx' search (where xxx is the name of the search engine).