How to Download Mozilla Firefox for Free
Mozilla Firefox is a free and open-source Web browser for the Windows, Linux and OS X platforms that serves as an alternative browser to the default browsers included on those operating systems. Regardless of which type of computer you have, you can use your operating system's default browser to connect to the Internet and download Firefox from Mozilla's website.
Log in to your computer and open your Web browser. For example, click the "Internet Explorer" icon in your task bar to open Internet Explorer.
Open the main Mozilla Web page (mozilla.com).
Click on the green "Firefox 4" download button near the bottom left of the page. Note that the Mozilla homepage automatically displays the version of Firefox that's right for your operating system, so you don't have to go through a special selection process.
Click the "Save as" option if prompted. Browse to a location where you want to save the Firefox installation file if prompted. Then click "OK" or "Save" to download Firefox for free.