Postgresql 无法在 Windows 上安装 pg gem

我有两个Ruby版本:1.8.7、1.9.2和PostgreSQL 8.3.我不能在任何一个上面安装pg gem.获取此错误:

C:/Development/Ruby187/bin/ruby.exe extconf.rb
checking for pg_config... yes
not recorded
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
 --with-opt-dir
 --without-opt-dir
 --with-opt-include
 --without-opt-include=${opt-dir}/include
 --with-opt-lib
 --without-opt-lib=${opt-dir}/lib
 --with-make-prog
 --without-make-prog
 --srcdir=.
 --curdir
 --ruby=C:/Development/Ruby187/bin/ruby
 --with-pg
 --without-pg
 --with-pg-config
 --without-pg-config
 --with-pg-dir
 --without-pg-dir
 --with-pg-include
 --without-pg-include=${pg-dir}/include
 --with-pg-lib
 --without-pg-lib=${pg-dir}/lib

我知道这是一个常见的问题，但我还没有找到任何有效的解决方案...哦，我在路径中添加了C:\Program Files(x86)\PostgreSQL\8.3\bin.