"To make your own 404 Error Page, simple create an HTML page called error404.html and place it in your top-level Angelfire directory. You can use the page to link back to your homepage or promote specific parts of your site. What appears on the 404 Error Page is up to you. The only requirement is that the finished page must be at least 512 bytes in size."
From https://www.angelfire.lycos.com/popup/webshell/error404.tmpl

I've made a error404.html page. (http://brischri.angelfire.com/error404.html) but if I type http://brischri.angelfire.com/zut answer I receive is the angelfire's 404 page.

  Christian