Just want to provide my experience as it is a little different than what has been said. In my case, I had a new Windows 10 computer and installed Turbo Tax Deluxe 2019, registered it and closed it without starting my taxes. A few days later I attempted to start my taxes and received the request to re-register. I did not re-register, but found my way to this forum. Thanks to everyone providing a little insight I was able to find a solution. I removed all external USB drives and equipment, which did not help. Because it was a new computer I had no Anti-Virus or firewall outside of what Windows 10 provides, but I turned those off to no avail. I turned off my VPN and did not allow it to start when I booted - no help. After seeing others talk about removing external USB drives, it got me thinking about the drive I added after installing TT - an internal hard drive connected directly to the motherboard. I temporarily unplugged this drive, rebooted Windows and sure enough, TT opened without requesting me to re-register. I will need to complete my taxes before putting this drive back in as doing so caused the re-registration to appear again. As others have said, DO NOT continue to enter your activation code multiple times. If you are receiving the re-registration there is likely something you can turn off, un-do, uninstall or remove to get it working. Not that you should have to.
