Your serial number can be found in your purchase receipt e-mail. Be sure to keep your serial number in a safe place. Without it, you can not authorize your products. If you have purchased directly from the Heavyocity store, your serial number will be automatically registered to your account. If you purchased from a retailer, be sure to register your product in your account page at heavyocity.com for updates, downloads, and offers.
If your product is a "Powered by Kontakt" or "Powered by Reaktor" product, you can find the serials for your registered products by logging into your account on the Native Instruments website:
https://www.native-instruments.com/en/my-account/my-products-serials-downloads/