Alternatively you can manually enter the activation code. See here.
Enter your e-mail address and click on.
-> When registering an activation mail is automatically send to the entered e-mail address. As soon as you click on the link the registration is finished. See above.
Enter your username and your activation code from the e-mail and then confirm by clicking on . If you did not receive your activation code then in Login dialog, click on Resend activation mail (see here).