I am not sure what you mean when you say "last download license". If your concern is that you will be using up your second activation that you are allowed that is possible (you are allowed to have the software installed/activated on 2 machines) but not necessarily so since it is the same machine.
If you run into a problem you can always contact Adobe Support directl by chat or by telephone and have them reset things for you.
Here are some links to help make contact:
Well, you would at least have to tell us what Adobe products you are referring to so we can advise more specifically...