I have been trying for over 24 hours to install Inventor 2015 from the education section of the website. I have tried the installation directly from the page over a dozen times with the end result being a network error message every time. I have gone as far as to disable all firewalls and virus protection during 6 of the attempts. I have also downloaded the files directly 3 times, and in every instance when I try to use that method of installation I get a message that there are files missing from the download. This is extremely frustrating. I have been able to download and install Autocad with no issues at all, this problem only seems to happen with Inventor.
I would recommend that you try downloading your product using the virtual assistant by following the directions here:
http://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/How-to-...