Windows Apache MySQL PHP. There are a few WAMP installers out there including EasyPHP and WampServer (XAMPP for Mac). I prefer WampServer since it comes with an easy to use service manager as a tray icon. The service manager allows you to choose versions and manage all the extensions (modules) of apache, php, and mysql. This way, you don't even have to edit any configuration files manually. You cant get it any easier!
Download and install WampServer
Download WampServer from their website.
WampServer can be downloaded from SourceForge too
Now run the installer and follow the instructions. Its better if you do not install it in C: drive (where you have Windows installed).
You are now ready to run your php files
Now open your browser, and visit http://localhost. This is the host that runs in your local machine. Click on the WampServer tray icon, then click 'www directory'. Now if you place a file named 'test.php' in that directory, you can run the file from your browser using this link http://localhost/test.php.
For managing your MySQL databases using phpMyAdmin, visit http://localhost/phpmyadmin.
Hope that helps :)