Downloading Lightroom onto a new laptop

Hi,

I need to download my Lightroom version 5.0 onto a new laptop.

I have searched extensively on the Adobe site and the help functions but have not been able to find a simple download link that would enable me to download Lightroom 5.0 onto my laptop

could someone please provide this download link?  I will then insert my serial number to make sure I can download it.

with thanks and best wishes

Ariel