GraphViz::Makefile is pure perl, so as a last ressort you can install the module by copying it to ActivePerl's site library (but using CPAN.pm or another PPM repository would be better). The problem might be GraphViz, which has additional external dependecies. But also here: try to find the ppm at another PPM repository. I think there's even a repository maintainer to whom you can send ppm requests.