You will need your registration key. You can upgrade your existing one
to unlock 4.2, do so by going to: http://www.bioinfor.com/keyupdate.htm
If you don't receive an email with the download link please go to:
http://www.bioinformaticssolutions.com/products/peaks/supportform.php
to ask for it.
Merry politically correct holiday everyone!
-IainR