Have an issue using .htaccess to change HTML to PHP -

i have site loads of html files of them require little php functions. have heard .htaccess can handle , tried code below ...

removehandler .html .htm addtype application/x-httpd-php .php .htm .html 

... when if open page asks me download .php file

this suggests not have mod_php installed or enabled.

the web server needs know how handle php files want handle php.