Steve, the XAMPP install is limited, true, I found it in the end to be not what I wanted. It will not run properly if you try to set it up in an established Apache server. That is just a foolish thing to do, so why even try it? I cannot believe that anyone with any experience with Server technologies would not immediately recognise the problem and know how to resolve it.
The Xampp installer was designed for people who have little or no experience with server technologies so it is a one-stop installer. Setting up PHP and MySQL on IIS is just as much of a nightmare as using XAMPP. We, or more accurately I, opted for the WAMP option and have never regretted it. I administer two small installations as well as my private ones without problems, Three WAMPs, one LAMP, but I cannot get access to the Linux server, only the Moodle folders. (Can't say that I blame them, who wants me stomping around inside their server when I know so little about Linux?)