[snip] I finally managed to test this out and step 4) is not quite right. It should be as follows:
4) Install Inline-0.44 from CPAN by running: set perl5opt=-MConfig_m perl Makefile.PL dmake test dmake install Similarly, when you run an Inline script for the first time the 'perl5opt' environment variable needs to be set to '-MConfig_m'. After the C code has been successfully compiled, it doesn't matter whether the perl5opt environment variable is set or not. Setting that environment variable just means that *whenever* 'perl' is called, 'perl -MConfig_m' is actually called - which means that the %Config::Config values from Config_m.pm are loaded. There are also times when that environment variable needs to be *unset* - eg, if you were to build the PAR module from CPAN, I think you would find that perl5opt needs to be unset, and you would then build PAR by running: perl -MConfig_m Makefile.PL dmake test dmake install But most of the time it won't make any difference whether perl5opt is set or not. [/snip] Rob, thanks for all of the insight, it has been a huge help!