browser showing content of install.php

When I try to install wordpress using url https://localhost/wordpress/wp-admin/install.php, the browser(firfox) is showing the content of the install.php(including all php tags) page. I am sure that my server is configured with php because I created a sample php page with echo ‘hello world’ and browser is rendering properly.

My folder location of wordpress in server is C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\wordpress

Should I need to make any entry in httpd.conf of apache server for wordpress. Please help