I tried it in Internet Explorer 8 and it did not work just as you reported but
why can't you just download from the Files area/web page by scrolling down to
the M4 package? It just takes much longer this way.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
The M4 page ( http://gnuwin32.sourceforge.net/packages/m4.htm ) seems to have
an incorrect link for "Complete package, except sources". The Setup link says
http://downloads.sourceforge.net/gnuwin32/m4-1.4.14-1-setup.exe but when
clicked, the page https://sourceforge.net/projects/gnuwin32/files appears.
So, the download does not happen.
I tried it in Internet Explorer 8 and it did not work just as you reported but
why can't you just download from the Files area/web page by scrolling down to
the M4 package? It just takes much longer this way.