How to add a favicon
Place the favicon.ico in the Joomla root directory and add these lines to rt_head_includes.php (or index.php if you use an old template):
<link href="/favicon.ico" rel="shortcut icon" type="image/x-icon" />
<link rel="shortcut icon" href="http://yoursite.com/favicon.ico" type="image/x-icon" />
If you have favicons located elsewhere, delete them and their code references.
Still doesn't show up? Clear cache and delete all temporary files and
restart your browser.
If this doesn't work in IE then please check that the favicon is a valid Windows icon.