Can't run php code from inside html file

[Rune-Boards.Com]

I am having a problem running my php code from inside an html file. I have tried the .htaccess method and the handler method. I'm using a webserver with cpanel(version 11), apache(2.2.15) and php(5.2.13).I have also tried the files on xampp and they work perfect, but when I upload them to the webserver the php code from inside the html will not run.Any suggestions, please?