I have reimaged my PC and have had to re-install the fore mentioned software. When re-activiating after re-install with the original serial number, I receive the following message "Please enter a valid serial number".
uninstall your acrobat dc
restart your computer
reinstall your acrobat dc and activate with your serial number
Single user licensee downloadable installation files available:
And a big thank you to Jim @ Prodesigntools for helping me with these links!