you cant, but the web page your'e visiting sometimes puts its own icon which will change the E. In the case of wackbag.com ... we change the E into a little WOW icon... BUT once you clear your temporary internet files, its gone
to get it back
remove wackbag from your bookmarks
clear your temporary internet files
shut down browser then restart
go to wackbag.com, make a new bookmark
next time you start up your browser, wackbag will have the little WOW icon in the URL window and the bookmark.