Your gateway has three predefined login accounts: admin, user, and support. You will normally use the admin account to configure the gateway. Its default password is admin. You can change the password for the admin account from the Device page of EasyConfigurator.
From the Device page, click on Change Password. This window appears:
Enter the current password followed by the new password (enter twice to confirm). Then click Apply. The gateway will automatically restart.
Note: the default passwords for the user and support logins are user and support, respectively. You can change these from the gateway's Web user interface. Just go to the Security menu and select Device Login.