Remove spaces from file names, and use proper case for extension.
%%\begin{wrapfigure}{l}{60mm}
\begin{figure} [ht!]
\centering
%%\begin{wrapfigure}{l}{60mm}
\begin{figure} [ht!]
\centering
-\includegraphics[width=60mm]{"Cluster x Nodes NX=150 and NX=170".JPG}
+\includegraphics[width=60mm]{Cluster_x_Nodes_NX=150_and_NX=170.jpg}
\caption{Cluster x Nodes NX=150 and NX=170 \label{overflow}}
\end{figure}
%%\end{wrapfigure}
\caption{Cluster x Nodes NX=150 and NX=170 \label{overflow}}
\end{figure}
%%\end{wrapfigure}
\begin{figure} [ht!]
\centering
\begin{figure} [ht!]
\centering
-\includegraphics[width=60mm]{"Cluster x Nodes N1 x N2".JPG}
+\includegraphics[width=60mm]{Cluster_x_Nodes_N1_x_N2.jpg}
\caption{Cluster x Nodes N1 x N2\label{overflow}}
\end{figure}
\caption{Cluster x Nodes N1 x N2\label{overflow}}
\end{figure}
\begin{figure} [ht!]
\centering
\begin{figure} [ht!]
\centering
-\includegraphics[width=60mm]{"Network latency impact on execution time".JPG}
+\includegraphics[width=60mm]{Network_latency_impact_on_execution_time.jpg}
\caption{Network latency impact on execution time\label{overflow}}
\end{figure}
\caption{Network latency impact on execution time\label{overflow}}
\end{figure}
\begin{figure} [ht!]
\centering
\begin{figure} [ht!]
\centering
-\includegraphics[width=60mm]{"Network bandwith impact on execution time".JPG}
+\includegraphics[width=60mm]{Network_bandwith_impact_on_execution_time.jpg}
\caption{Network bandwith impact on execution time\label{overflow}}
\end{figure}
\caption{Network bandwith impact on execution time\label{overflow}}
\end{figure}
\begin{figure} [ht!]
\centering
\begin{figure} [ht!]
\centering
-\includegraphics[width=60mm]{"Pb size impact on execution time".JPG}
+\includegraphics[width=60mm]{Pb_size_impact_on_execution_time.jpg}
\caption{Pb size impact on execution time\label{overflow}}
\end{figure}
\caption{Pb size impact on execution time\label{overflow}}
\end{figure}
\begin{figure} [ht!]
\centering
\begin{figure} [ht!]
\centering
-\includegraphics[width=60mm]{"CPU Power impact on execution time".JPG}
+\includegraphics[width=60mm]{CPU_Power_impact_on_execution_time.jpg}
\caption{CPU Power impact on execution time\label{overflow}}
\end{figure}
\caption{CPU Power impact on execution time\label{overflow}}
\end{figure}