Unknown graphic extension and file not found in beamer

Question

The header of my file is the following:

\documentclass[xcolor=x11names,compress]{beamer}

\usepackage{times,amsmath,amsfonts,psfrag}
\usepackage{latexsym,amssymb,float,stfloats,multirow,subfigure}
\usepackage{graphicx,subfigure,epsfig,color}
\usepackage{tikz}
\usepackage{xcolor}
%\usepackage[pdftex]{graphicx}
%\usepackage{sidecap}
\usepackage{cite}

and I'm including the figures as follows:

\begin{figure}[h]
 \centering \epsfig{file=mainfigure,scale=.62} %\caption{Cognitive Radio Pair}
\label{fig:CR_pair}
\end{figure}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\begin{columns}
    \begin{column}{2.6in}

\begin{itemize}
\small
\item[$\bullet$] $\underbrace{\text{At each step of sequential estimation}}_{\underbrace{\text{\small CR pair decisions}}_{{\text{\small \textcolor[rgb]{1.00,0.00,0.00}{1. Terminate}\qquad} \underbrace{\text{\textcolor[rgb]{0.00,0.50,0.00}{2. Continue}}}_{\textcolor[rgb]{0.00,0.50,0.00}{\bigg\Downarrow \qquad \qquad \bigg\Downarrow}}}}}$\\
  \qquad \qquad \quad \textcolor[rgb]{0.00,0.50,0.00}{Same channel\qquad Switch}
    \end{itemize}
  %\end{block}
    \end{column}
    \begin{column}{2.5in}
    %\begin{block}{}
% Your image included here
%\begin{figure}
    \centering \includegraphics[trim = 10mm 25mm 10mm 10mm, clip=true, width=1\textwidth]{mat-model-new3.eps}%\caption{Risk versus cost}
%\end{figure}
%\begin{center}
%\end{center}
%\begin{figure}[th]
% \epsfig{file=risk_vs_c_snr_-10db_0db_alpha0-15.eps,scale=.41} \caption{Risk vs cost SNR=0,-10 dB}
%\label{fig:risk_vs_c}
%\end{figure}
    %\end{block}
    \end{column}
  \end{columns}

then when I hit texify I get these two following errors:

File mainfigure not found

and

Unknown graphics extension .eps

FYI, I tried to install all the related package in Miktex packages manager but still doesn't work. Any help please?!!!!