Here, fill in your registered e-mail address.
Typically this will be the e-mail address from which you made your payment.
To get your hardware ID:
1) Start GTO+
2) Go to "register" in its menu
3) It's the code that looks like 1559-121F-QC6B-BB42-4828-00C4-687E
If you own one license, then just fill in 1 in this field.
If you own two licenses, then fill in either 1 or 2.