You first need webserver software on your local machine. You can either download apache from apache.org, or (if you have XP Pro) you can use the built-in Microsoft IIS server.
After your webserver software is in place, you need to download the latest PHP 4 (not 5) installer from php.net and install and configure it with your server sortware you installed in the previous step.
After you get you basic webspace up and running on your local machine, you should download and install mysql for Windows. It should also be configured into your webserver.
http://dev.mysql.com/get/Downloads/M...m/pick#mirrors
Next, get phpMyAdmin (
http://www.phpmyadmin.net/home_page/downloads.php ) to allow you to manipulate your mysql databases via a web interface. (install this into your webspace)
Lastly, get phpbb from phpbb.com and install it into your webspace.
There...that is how you would manually install everything for a basic test server. I'm sure there may be an easier way...