I use the following code to try to include a graph ( .ps file) in my latex docuements.  It works in unix environment but it doesn't work with MikTex.  I wonder why.

\begin{figure}[htb]
\label{indiff}
\centering
\includegraphics[scale=2]{image1.ps}
\caption{Renegotiation-proof compensation }
\end{figure}

When I run the command pdflatex, I got the following error message: