Why does my activation key only last 90 days?

The firmware itself is lifetime. Activation keys are set to 90 days because lifetime keys are not stable on the key server. The 90 days count from when we activate your key, and the activator app shows how long is left. Ask in a ticket for a new key before it runs out, and you get it free. When a key runs out, you can no longer unlock the card to read or write memory after you restart your main PC.