I recommended DB_File because it is already included with Perl. I don't use ActivePerl much so can't really advise on how to fix your install issues. A guide to installing modules for Win32 might help. Or just install Strawberry Perl and install the modules via CPAN.
For a DB of this 1-2GB size, I would be thinking along the lines of MySQL. Its free and its supposed to work pretty well and Perl has fantastic SQL I/F. I'm thinking about this for one my apps, but don't have experience with it yet.