Php and informix 7.x

Hello my name is harold I have a question you can help me? My question is how configurate Php with Informix 7.x I saw the manual in www.php.net but my application in php not run well, it show an error: "Module can not load" I couldn't set the variables: (This is the manual in www.Php.net) Make sure that the "INFORMIXDIR" variable has been set, and that $INFORMIXDIR/bin is in your PATH before you run the "configure" script. The configure script will autodetect the libraries and include directories, if you run "configure --with_informix=yes". You can overide this detection by specifying "IFX_LIBDIR", "IFX_LIBS" and "IFX_INCDIR" in the environment. The configure script will also try to detect your Informix server version. It will set the "HAVE_IFX_IUS" conditional compilation variable if your Informix version >= 9.00. where is the configure script? How install the extension php_ifx for informix in Windows NT? Thanks in advance. Harold.