Here’s a wonderful article on how to install Apache, PHP and MySQL on Windows Vista and 7 by Vaishnavi.

Quotting from the article:

This tutorial will teach you how to install and configure Apache 2.2.11 + PHP 5.3 + MySQL 5.1.36 and PHPMyAdmin 3.2.0.1 for Windows Vista & Windows 7 in a step by step manner. There is also a screencast available.

Link: http://webdevcodex.com/tutorial-installing-apache2-php5-mysql5-phpmyadmin3-windows-7-vista/