User name
The user name is the e-mail you have used during the registration process. If you have changed this under settings you will have to use that e-mail.
Password
The initial password has been sent to your e-mail which you have used during the registration process. If you have changed this under settings you will have to use that password.
Save username on this PC
If you activate this option a cookie is set on your PC. Your user name will then be filled automaticaly into the appropriate field at the next login progress and you only have to fill in your password.
Forgotton password
Should it happen that you forget your password, then you can request your password which will then be send to you by e-mail. Be sure to use the same e-mail as you defined for the login process.