Nope - PHP, by default, is on for every user, regardless of their configuration. Are you sure you uncommented the "AddType" lines? These lines tell the PHP module that .php files should be interpreted - if they're not there, then the browser would just send the results straight to the window, with no processing.
Check that the AddType's are uncommented, and check that the phpinfo line is correctly in that file. Then, load it in your browser, and if there's still nothing there, do a "view source" and see if there's anything in the HTML.