I had the same circumstance, multiple requests to re-enter activation code when starting TurboTax. I had used TT repeatedly in prior days without being prompted to re-enter code. The I noticed I had a USB drive plugged in now, that was NOT there when I initially installed and activated TT. I believe TT takes note of your system at startup (CPU, RAM, Storage, etc) to identify each installation of your allotted 5. I removed the USB drive and TT started with incident. If you change your computer, even the temporary addition or removal of external storage, TutboTax will see it as a"different" computer. Lots of people having this problem, lots of interesting fixes... I just picked yours, because it was typical of the event. Good luck.
