siuntx \micro symbol not shown

Question

When I compile the next code the micro sign doesn't shown:

\documentclass[12pt,twoside]{report}
\usepackage{amsmath,amsthm,amssymb,amsfonts}
\usepackage{color}
\usepackage{siunitx}
\pagestyle{empty}
\begin{document}
    \SI{100}{\micro\metre}

    $\SI{100}{\micro\metre}$
\end{document}

I also copied and tried to compile the code given in siunitx: µ doesn't work :

\documentclass{standalone}
\usepackage{fontspec}
\usepackage{siunitx}

% Note that the sign must be
%  µ
%  MICRO SIGN
%  Unicode: U+00B5, UTF-8: C2 B5
% and \emph{not}
%  μ
%  GREEK SMALL LETTER MU
%  Unicode: U+03BC, UTF-8: CE BC

\sisetup{math-micro=\text{µ},text-micro=µ}

\begin{document}
Now you can \si\micro\ all the things.
\end{document}

But I get a 'Fatal Package fontspec Error: fontspec package requires either XeTeX or LuaTex.'

I am using MikTex2.9.

What can be done??