Next, we need to get the first of three required libraries to supplement NetPbm. The libpng library is used to manipulate and convert (to and from) png file type. Fortunately, it comes with an installation program. Download libpng-1.2.37-setup.exe and save it to our `Netpbm' folder (inside the `latex2html' folder on the desktop). When you double click that exe file, it should know where to install because it looks for the NetPbm (GnuWin32) directory. However, if it does not recognize that you have installed NetPbm (GnuWin32) at C:\texmf then you must tell the installation program to install to the C:\texmf\GnuWin32 location.