I am running CakePHP 1.3 setup on a windows 10 PC with Visual Studio Code. I have configured VSCode to use an extension for IIS Express to enable both run and debug for web application using Vscode and IIS Express.
When I open the application folder using vscode and run the cakePHP application using said command for the extension i get the error message How do I solve HTTP Error 500.0 - Internal Server Error
In output i can see IIS Express server running in the , see print screen below

when call the URl http://localhost:11386/index.php on chrome i get Internal Server Error, see print screen when accessing the application on chrome below

I was able to resolve it as it seems the root cause for the HTTP Internal Error was IIS Express was not enabled to use PHP.
To enable PHP on IIS Express, install PHP and update applicationhost.config in (%userprofile%\documents\iisexpress\config\applicationhost.config)
In the applicationhost.config file search for
<fastCgi/>tag entry and replace it with the below, pointing to the directory where your PHP has been installedwith this settings, Visual Studio Code is able to run PHP applications using this VSCode IIS Express extension