Incorrectly editing the registry can crash your system. Only explore if you are comfortable.
This article covers everything you need to know: what these numbers are, where to find them, how to recover them if lost, how to handle Intuit’s discontinued support, and legal/security considerations for running such an old version. quickbooks pro 2013 license and product number
Unlike modern cloud software which utilizes continuous authentication tokens, QuickBooks Pro 2013 relies on a static validation architecture. Incorrectly editing the registry can crash your system