oh, sure, no problem.
I added on the xampp folder and/or the htdocs folder as part of the URL.
And of course it did not work...because the file was not in that folder, but I thought that I had to add on the 'htdocs' part.
I have used IIS for many years and develop mostly in .NET so I am just getting used to the settings for apache.
localhost/index.html and localhost/index.php work fine...of course.
I have also added on a new folder in the htdocs 'TestPHP' and this URL works fine:
It ran the PHP script and printed to the screen "Hello World" as the PHP code indicated. I did not realize that it (apache) would run automatically from the htdocs folder...now I know...