I am the ONLY person running T on a single Mac. Every time asks me for an activation. Today, it claimed that I installed it on 4/5 computers. That's false. What can I do?

I have installed my Turbotax on just a single Mac with a Firewall enabled (and NOT on four computers). Is there a way to deactivate the other computers? My current computer count should be 1/5 and not 4/5.