See this thread: http://lists.gnu.org/archive/html/emacs-orgmode/2011-10/msg00792.html
You need to copy libpng (or whatever dll) to your emacs bin directory - directory where runemacs.exe is located.
See this thread: http://lists.gnu.org/archive/html/emacs-orgmode/2011-10/msg00792.html
You need to copy libpng (or whatever dll) to your emacs bin directory - directory where runemacs.exe is located.