If you don't already have Perl, or have an older version, you'll need to obtain and install version 5.004 or later. Pre-compiled binaries are available for many platforms.
You will also need the Net::FTP and Net::SMTP modules, which are part of the libnet bundle. Follow the instructions included in the archive.
For Windows NT, this pre-built binary package works well, and it already has the libnet bundle compiled in. Uncompress it to a temporary folder, run install.bat, and follow the prompts.