In case you have lost or forgotten your password, you can find the option "I have forgotten my password" on the "Sign in" thumb index. You will be e-mailed a temporary password, at the address you gave when you signed up. Do change it as soon as you can.
In case the e-mail address you used to create your license is no longer active, do contact us directly on the Guitar Pro customer support area, with a brief explanation of your problem.