When you start over, if it asks do you want to go online for updates. Tell it No. This forces it to just use the install file.
If that does not work, you can download the full install ISO file and burn it to a DVD. Then when you run it inside Windows 7 or 8.1, you can disconnect from the web to force it to just load the original.
I think the problem is MS' servers are totally bogged with folks doing the upgrade to Win 10. The update process is probably very low priority until 29 July.
If that does not work, I can send a Win 10 DVD I made for the install to try. Only takes 2 days to CO.