how do I change the shortcut icon
I created a shortcut on my desktop for Facebook and the icon on the shortcut has a picture of the Mozilla icon instead of the Facebook icon. How do I change the icon from Mozilla icon to the Facebook icon for my desktop?
Opaite Mbohovái (2)
Right-click the shortcut you created, click Properties, and then click Change Icon.
You can try to toggle the browser.shell.shortcutFavicons pref on the about:config page.
You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.
If you want a different icon (favicon) then you have to assign that icon yourself to the desktop shortcut (right-click: Properties). You can usually get the favicon if you append "favicon.ico" to the main domain of a website (e.g. http://www.mozilla.com/favicon.ico) to display the favicon in a tab and save that image to a folder or see if you can find it in "Tools > Page Info > Media".