Trouble getting pkg-config to work in Windows

["Stewart Weiss" <stewart weiss acm org>]

I have spent many hours trying to get a version of pkg-config
to work properly on my Windows XP system. I have installed GTK+
following instructions in various webpages. In the last attempt,
I used http://www.ibiblio.org/apollo/WinGtkHowto.html as my guide.
I have downloaded a few versions of pkg-config binaries, the last of
which is pkg-config-0.20 from the gimp.org download page.  I also
tried building from source, but I have the same problem.

The problem is that when I run a command such as 
    pkg-config --cflags gtk+-win32-2.0
I get the message

Package gtk+-win32-2.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gtk+-win32-2.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gtk+-win32-2.0' found

This will happen regardless of which package name I use. All of the .pc
files are in the top/lib/pkgconfig  directory, where top is the name of
the directory that contains bin/pkg-config.exe. I have tried setting the
registry to create a key and values for PKG_CONFIG_PATH, but this does not
work.  I have tried manually setting the environment variable, to no avail.
I get this message no matter what.

Does anyone know what the problem is?

Stewart