Hey,
So, PHP 5.4.16 is a version that satisfies the requirements, so it should work without any issues.
However, it looks like your server is not properly configured to execute the .php files. Can you please try to run the PHP info file that I've attached here and let me know if you are able to see the result in a browser or it is downloading the file again.
If the file is still being downloaded, I would suggest you contact your hosting provider so they can help you to set up the server properly.