Below are instructions to set up your machine for PHP environment. I’m using Windows XP Professional SP2.
Download the Win32 Binary (MSI installer). Double click on the downloaded installer and install. The version I’m using is Apache 2.0.59 and I installed into C:\Program Files

Apache installation wizard
Download PHP. I’m using PHP 5.0.2 . Install it to C:\php.

PHP setup wizard
(3) The next step will require you to copy these 3 files from C:\php to C:\Program Files\Apache Group\Apache2
(a) php5ts.dll
(b) php5apache2.dll
(c) php.ini
(4) Open php.ini in C:\Program Files\Apache Group\Apache2 using any text editor. Find “doc_root” and edit it to
doc_root = C:\Program Files\Apache Group\Apache2\htdocs
(5) Go to the directory: C:\Program Files\Apache Group\Apache2\conf\ and open httpd.conf file for editing. Add those lines at the end of the file.
LoadModule php5_module php5apache2.dll
AddType application/x-httpd-php .php
(6) In the same file, look for “DirectoryIndex” and edit it to
DirectoryIndex index.html index.html.var index.php
(7) START THE SERVICES
Start the service and the service icon will appear.

(8) TEST APACHE WEB SERVER
After all the installations are done, all you haev to do is to test them out. Open your browser and type http://localhost/ or http://127.0.0.1/ The page will display test page for Apache.
(9) TEST PHP
Go to C:\Program Files\Apache Group\Apache2\htdocs, create a new PHP file using notepad.
Save the file as “test.php”
Write the following codes in the PHP file and save it:
<?php
echo “testing for PHP”;
?>
Open a new browser and type http://localhost/test.php

If your browser display the same, it means that you have succesfully set up the Apache and PHP.
AN EASIER WAY TO SET UP
If you find that installing Apache web server, PHP and MySql seperately give you lotsa headache, you can always try to install EasyPHP. It consists all the installation with just a click.

EasyPHP setup wizard
Install it to C:\
Then try to create a test php page (just like the one I created earlier. Place it at www folder.
Start the service.
Open a new browser and type http://localhost/test.php
If your browser display correct page, thus, you’ve successfully installed EasyPHP.