Many of our sites have their own little icon, the system reads the sign at the time when the view pages starting with the root directory of your project read to see if favicon.ico file, if there is a direct display this icon, if not, it will go webapps / root / down to find this file, if these two places are not, then the IE icon on the display.
Another form is to modify the page
<link rel="shortcut icon" href="favicon.ico" type="image/x-icon" />