John, thank you for your answer. I need to clarify the problem. When attempting to activate the software on the 2nd computer I am logged in to my TurboTax account, and it already knows my license key, the last 4 digits which it provides, and the system reports that the software is registered to me and is currently installed on one of 5 computers (which is correct). The license key number matches the one sold to me by BigHomeTax so everything looks good. But within a few moments, when the software is in process of activation on my 2nd computer, the system reports a fault Error Code 605 and states that the license is invalid. Does that help? Appreciate your advice, thank you.
