I'm not sure about using Gtk2-Perl, but if you are developing under Windows XP, ActiveState Perl is very easy to use and install, and installing modules, even ones that aren't approved by ActiveState is fairly easy as well.
You can get it here: http://www.activestate.com/solutions/perl/
Comment on Re: Installing Gtk2 using PPM on Windows
Installing modules under ActiveState is easy when there's a ppd, but there isn't any ppd available in any of the public repositories that are commonly known. So the OP has to compile it. (Or maybe request kobesearch to do it).