Gtkmm-Win32 and Dev-Cpp

["Jamiil Abduqadir" <jalqadir gmail com>]

I have recently installed Gtkmm-2.4 on my MS-Windows XP box. Following
the installations instructions given in the documentation for Dev-Cpp,
I installed it at the 'C:\Dev-Cpp' subdirectory.
Now, when I type 'pkg-config --cflags gtkmm-2.4' at the prompt I get a
message saying:
Pakage gtkmm-2.4 was not found in the pkg-config search path. Perhaps
you should add the directory containing  the file to the
PKG_CONFIG_PATH environment variable..."
I did as suggested by the message, however, I now get the same message
about 'libpng12'; only this time I could not find the file in my
sistem.
Can anyone help?!!

TIA