Oh well... The GD library has a few dependencies by itself. Here's a list of suspects:

• libfreetype_6__.dll
• libiconv_2__.dll
• libjpeg_9__.dll
• libpng16_16__.dll
• libtiff_5__.dll
• libXpm__.dll
• zlib1__.dll

That's just from the strings in libgd-3__.dll, I can't say whether the list is comprehensive. I'll probably get some time to experiment on my Windows box in a few days.

As an aside: As far as I can say, You don't need to provide the absolute path to the libraries. pp should find them as they're on pp's path.