Installing moodle 2.5 with external database (MS SQL)

Hi,

Has anyone tried to setup moodle using an external database such as MS SQL? Is there a step by step guide available here? I tried doing this on Virtiual Box but I cant seem to connect to my Database Box.

Below are the details of my setup;

OS: Windows Servedr 2008 R2 Standard

Database: MS SQL 2008

Web Server: IIS 7

PHP: 5.3.28

What ports should I allow on my Web Server box and Database box?

 Thank you guys in advance.