Confessing how embarrased I am, I'm asking anyway. How do you switch browsers, and do you have to do a lot of stuff to or with your computer to do it. If so, I'd best leave well enough alone.
No, all you have to do is install it. Firefox won't do anything to your Internet Explorer, although it may ask you if you want Firefox to be your default browse. You're free to say no. If you find that you don't like it, you can just go back to using Internet Explorer. I should mention that Firefox is capable of importing your settings and bookmarks/favorites from Internet Explorer, so you don't have to waste a lot of time customizing it.