pgfplots contour example error

Question

I'm reproducing the following example from pgfplots manual.

\begin{tikzpicture}
\begin{axis}[view={0}{90}]
\addplot3[contour gnuplot]
{x*y};
\end{axis}
\end{tikzpicture}

But this code produces the following error:

Package pgfplots Error: sorry, plot file{Example_contourtmp0.table} could not be opened.

I would highly appreciate if you point me what I'm missing. Thanks

P.S. I'm using MikTex 2.9 on Windows 7.

Edit

Following @hpesoj626 guidelines, I got the following error message.

Answer 1

You need to ensure that the path is set correctly. One of the most common frustrations with Windows is the tiny text box used for setting up paths. For any executable to be found one needs to set the "path." Different versions of Windows have slightly different ways to navigate to the input screen, so is best to rather click on "control panel" and search.

An easy way to see, if a path was set-up correctly is to fire up a command prompt console and to type path:

As you can see, easy is an understatement, as is all cluttered under anything close to defaults. If you right click at the top left of the console you can set your console to something larger. You can also adjust some colours if you wish. Good inspiration for color schemes can be found at the sublime2 editor.

A good standalone "Gnuplot" comes bundled with Octave and all necessary settings for windows.