Password setup for httpd.conf file

I've added the directives to the Httpd.conf file as per apache tutorial.
However, I'm still not getting a popup requesting user name and password.
I've created the password file. Do I need to enable this with any other
directives? I'm not getting an error and the web site run fine, it's as
though the directives I added are not enabled? Also, where exactly should I
enter the directives in the httpd.conf file? Does it matter. Thanks in
advance. Windows Xp machine.