How to Set Up A Custom 404 File Not Found Page on Apache

http://webdesign.about.com/od/apache/ht/ht404apache.htm

1. Create a Web page that will be your 404 document.
2. Open yourhttpd.conffile or .htaccess for editing.
3. Find the line that reads (or add the line)

    ErrorDocument 404 /404.html

4. Change the third entry to the URI you would like to display, e.g.

    ErrorDocument 404 /new_404.html

5. Restart your Web server if necessary.