Saving PNG files using Win32 PIL

[Loris Caren]

I've writen a script to generate PNG images using PIL.  It works a treat
under Linux, but when I try to port it to MSWindows, the
PIL/PngImagePlugin spits saying that I don't have a zip encoder. I
already have a copy of pkzip, but I got hold of a copy of gzip.exe and
stuck it in C:\Windows\zip.exe but to no avail. Can anyone confirm that
I need a zip executable, or is the PIL wanting a DLL, etc?