It's OK I was being a fool.
But Yes PHP is installed and working correctly.
I wrongly assumed, that when I read WP worked on IIS, that they meant a windows platform inclusing MS SQL.
This however isn't the case, It would seem I need to install basically everything that is Linux based onto my windows server from apache to mySQL.
This is something I am not prepared to do as it is a production server runing many websites under IIS6 , MS SQL and active state perl.
Although I do have PHP installed and running for some of my website apps, I cannot afford to run the risk of corrupting this server, or opening up security holes with additional webserver software or affecting MS SQL and it's performace by also running mySQL on the box.
I'm going to install everything locally on my WINXP machine just so I can play with WP and see if it meets our needs.