then you are configured to run php as a cgi - i do not recommend this.
i absolutely think it is better to build your systems from scratch - not relying on other scripts to do things for you. by doing this you get to understand how things fit together.
but you have a working apache installation so let's work with that.
unpack the latest version of php in the webserver/php directory.
create your php file and make sure you tell it where your extensions are to be found (usually c:/webserver/php/ext). do not try load any extensions yet.
right click on my computer and select properties. In the advanced tab, select environment variables. find the "path" variable in the bottom box and edit it to include "c:\webserber\php".
change the permissions on the files phpts, phpapache2.dll to allow execution by the user under whose credentials apache is running. do the same to allow write access to php.ini. If this is a dev box with no external access you might just make the whole directory world read-writable.
now add these lines to your httpd.conf file
Code:
LoadModule php5_module "c:/webserver/php/php5apache2.dll"
AddType application/x-httpd-php .php
PHPIniDir "C:/webserver/php"
restart apache. try your phpinfo test again.
now try to install mysql with the zip file from the mysql website. make sure you install it as a service when it asks you the question
once installed, copy the files libmysql.dll and libeay.dll from c:/webserver/php to c:/webserver/php/ext
now edit php.ini and uncomment the mysql extension. save and close the file.
open a command prompt and navigate to c:\webserver\php. type php and see whether you get any error messages. if not press CTRL-C and exit the command prompt.
restart apache again and try a phpinfo test.
personally i prefer always to create my own installations. that way i know they are secure and i also get a feel for how they will interact together and with my systems. on windows boxes i use IIS. unless you have the server version you can't use virtual sites but that's usually no big deal for a dev or desktop machine.