The Web Platform Installer (WebPI) is a simplified download/install experience for all of Microsoft's free web products. It includes everything that you need to get up and running to build your web solutions - from servers, tools, and technologies, including the most recently updated products. You can also choose from your favorite Web applications and Web PI will download and install not only the application, but the dependencies you need to run that application letting you get started more quickly and easily.
Windows XP SP 2,
Windows Server 2008