Red Hat Linux

and what version of that web browser?

RHL 5 probably shipped with an ancient version of Netscape Navigator, which would need to be upgraded.

I think this command should work... it works in Fedora Core distro's. Open CLI, and type "sudo yum install -y FireFox" or su - into root, and run "yum install firefox"

If those dont work I would try and go here
http://www.cyberciti.biz/faq/how-to-install-firefox-20targz-in-linux/

Google "install firefox on Red hat", you will find a bunch of How-to also....