On Thu, Mar 1, 2018 at 7:29 PM, Eli Zaretskii <eliz@gnu.org> wrote:

> > From: kensanata@gmail.com
> > c:/Portable Programs/emacs-26.0.91-x86_64/bin $ ls lib* | grep "png"
> > libpng-config
> > libpng16-16.dll
> > libpng16-config
>
> Where did you get those PNG DLLs?
>

These three files are in emacs-26.0.91-x86_64.zip which I got from
https://alpha.gnu.org/gnu/emacs/pretest/windows/