500 Error on SobiPro Frontend

Adding a SobiPro extention to Joomla 1.6.3 running windows 2008 server with iis7 and php 5.2.3 I ran into the following problem where sobipro system requirements failed stating that the XSL extention should be installed. Herewith The steps. 

Thanks to http://blogs.iis.net/donraman/archive/2009/10/16/configuring-php-extension-on-windows-a-simple-way.aspx

• Go to Control Panel
• Click on Add/Remove Program (Or, Uninstall a program)
• Select PHP MSI and click on 'Change'. Remember you should have installed PHP using the PHP MSI. If you have installed it using the ZIP file this won't work.
• You will see the below UI.

• Click on Next, following UI will appear.

• Click 'Change'

• Select 'IIS FastCGI'

• Chose the extension you want to install and click 'Next'.

• Click on 'Change'
• Click on 'Finish' on next screen and you are done.