You should E-mail Fengtao if you have lost your reg code. You will not get a reg code from anyone. They are unique to the user If you are a registered user.

Have you requested a new key using the auto send key using the email address you used when purchased? If your email address has changed, you will need to send a request to change the email address, as this is the way purchasers are kept in their database used to send new keys. You will need a new key going from version 2 to 3. There are places to do this on the support page.