Your js and css (C:\User..) are pointing to local paths, it will not work on server. use url or relative paths if the files are in server. Upload the css and js and keep it in same server folder and work like this ...
<link rel="stylesheet" type="text/css" href="shadowbox.css">
<script type="text/javascript" src="shadowbox.js"> </script>
OR if u have url's then use them on src & href accordingly.