Hello,

My first post. Please let me know if I am not following proper procedure.

I am VERY new to HTML and CSS. I'm following a tutorial I found online and everything was working fine until I introduced CSS. The tutorial had me set up an HTML5 webpage. Then we were being introduced to CSS. I followed everything exactly but the CSS file simply won't work in IE11. I downloaded Google Chrome and it works like a champ. I've run both the HTML5 and CSS through validators and everything comes up shiny! Could someone look at my code and make a suggestion? Thank you. My OS in Win 7 - all updates installed.
The HTML & CSS were written in Notepad.

Thanks again,
Don

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>HTML5 and CSS3 Fundamentals</title>
<link rel="stylesheet" type="text/css" href="styles.css" media="screen">
</head>
<body>


CSS
body {
font-family:arial,helvetica,sans-serif;
}

<header>