Your RegCodes are always located in your Store account. To get to them, do the following:
1) Go to https://www.mtu.com/catalog/login.php
2) Login to your account using your Email address
and your password
. If you have forgotten your password, you can reset it here https://www.mtu.com/catalog/password_forgotten.php
3) Once Logged into your Account, click on the Order to find the RegCodes for each order or scroll down to My Products
, and it will show you all of the Registration codes and Download Links.