So I had quite some difficulty with this at first. I was able to eventually get it to work. Several factors were prohibiting my install, such as Anti-Virus, which identified Start8 as a worm. Also, a couple of our network appliances were blocking the download process.
My resolution was to download the installer and the product key .csv "off the network" and place them on a flash drive. Then I disconnected the target PC from our network, disabled any anti-virus, and installed the application from the USB drive.
Worked the very first time.
Hope this helps.