Connect php to sql server 2005 express

We have a .net application which uses sql server 2005 or 2008 express. We have a seperate webservice and app that uses php to connect to our database. We have tried installing it on a Windows 7 machine using IIS and it works fine, connects to the database and the app is fast. On xp or Windows POS embedded (which is xp based but still supported on the hardware that we use) the driver for php and sql server have been installed but we cannot get php and sql server express to work together with iis or any other webserver. What we require is a solution that allows us to run a small lightweight webserver on these machines that runs php and connects to sql server 2005. The solution needs to be demonstrated to us and step by step documentation and any required software given to us