If you've registered an account and forgotten your password, you can reset it and have a new, randomly generated password e-mailed to you. However, this is only an option
if you specified an e-mail address during registration. If you decided not to do so, then your password cannot be reset and only the original password will allow access to your account. If that's the case and you can't remember your original password, you're welcome to just register a new account.