Reinstalled TI 2013 but hangs up

I decided to go back to TI 2013 and reinstalled it on a PC, Windows 7, 64 bit. It accepted the original product key, opened up the Get Started page with its three options then hung up. I just get a small spinning circle and the message at the top that it is not responding. I can close it down with Task Manager but not within TI itself.

I have uninstalled it, reinstalled it, used a cold boot twice, downloaded the latest version from Acronis and the result is the same each time.

I also stopped my AV program and Malware Bytes when I installed it.
Help! Anyone any ideas?