Favicons (favorites icon)
A favicon (short for favorites icon), also known as a shortcut icon, Web site icon, URL icon, or bookmark icon, is a file containing one or more small icons, most commonly 16×16 pixels, associated with a particular Web site or Web page.
Generating Favicons
There are many resources that help you generate favicons. A couple free ones that are useful are:
Using Favicon on 7cart
Most of your sites have a Content Area called "System Meta Default".
Insert a new content block (use the HTML Plain block) and enter the reference code that shows the favicon.
NOTE: Your favicon may not appear immediately after you've uploaded the file and posted the code... In fact, it may take a few days!