In the default document list in IIS management index.php is the first item enabled in the list. Is this what you are referring to? If not then what do you mean by "web server is not serving index.php files by default" ?
The OS is server 2008 R2. PHP is 5.3, MariaDB is 5.5, osTicket is 1.9.2 all of which is referenced as recommended in the installation document quoted in my original post. osTicket is being installed on an internal server for our own company internal use.
"Plesk, CPanel etc" _ I don't know what you mean by these. Are you saying it's something I should have installed ? All I'm trying to do is install osTicket on an internal server following the instructions supplied on the osTicket website. I have never used php before. I am a beginner at this, never installed osTicket before and am looking for help so I can use the product. Please remember Jack that you were a beginner once yourself; replies of an insolent nature are not helpful when people are struggling to understand something new. You criticise me for not supplying enough information and yet your answers do the same - I do not know what Plesk & CPanel are - please explain. Also, if you think the answer is "web server is not serving index.php files" then please explain this and how to put it right.