Turned out it was my desktop that is the problem. Even though I have the latest Win 10 updates installed, executed all the ipconfig command lines, adjusted the IPv4/IPv6 settings, disconnected my external USB drive, rebooted router, rebooted desktop, turned off my VPN, turned off my security software, uninstalled/re-installed TT 2021, nothing worked. However, once I installed TT 2021 on my Win 10 latop (of course with all the latest Win 10 updates), de-activated my VPN, deactivated my security software, no external USB drive, it installed/activated without any issues. I just wanted it installed on my desktop (aka server) because that's where I keep all my permanent software installed.
