Change Favicon

You could change Joomla Favicon on following steps :

1. You must have favicon.ico
    - you can create it on : Favicon Generator
    - also, you could make it with component : "Favicon", but just can run on Joomla 2.5
       with this component also you could place it with one-click
2. Place favicon.ico on /templates folder (administrator and site templates)

PS : in some third-party template (ex : JA/JoomlArt), also you must place favicon.ico on main /images folder on root