If you are talking about seeing Internet Explorer on the Immunizations page, it is because it is installed. I also use Firefox as my default browser, but SpyBot Search and Destroy also finds IE 8, Opera, and Firefox, because it's installed.
When you use Windows Update, that's also Internet Explorer. Many programs that access the internet use IE, so it must be immunized.
why does Spybot s&d keep saying that I use internet explorer when all I use is Firefox 3.6