How to use the fontspec package in a LaTeX document?

Question

I'm trying to make a simple document which uses the fontspec package in

1. Tex Maker 4.4.1 with LuaLaTeX engine.

Code I'm using

    \documentclass{article}

    \usepackage{fontspec}
    \setmainfont{Arial}
    \begin{document}

    \section*{Introduction}
    This is Introduction

    \end{document}

I'm getting this error message (although I've checked LuaLaTeX Engine is set in the drop down menu)

Tex Maker

The fontspec package requires either XeTeX or LuaTeX to function.

You must change your typesetting engine to, e.g., "xelatex" or "lualatex" instead of plain "latex" or "pdflatex".

Answer 1

I reinstalled the software and problem got resolved.