You could also download the ppm-packages as zips from http://www.activestate.com/PPMPackages/zips/6xx-builds-only/ ( or http://www.activestate.com/PPMPackages/zips/5xx-builds-only/ if your perl-version smaller than 5.6),
then unpack the zipfile (e.g. with winzip),
search for the file with the extension .ppd and
open a shell and change into the directory containing this file (lez call it Net-Telnet.ppd).
There you enter the following command:

ppm install Net-Telnet.ppd

Best regards,
perl -le "s==*F=e=>y~\*martinF~stronat~=>s~[^\w]~~g=>chop,print"