If you purchased your software from a retailer such as Walmart, Costco, Best Buy, etc., you'll be prompted to register every time you open TurboTax. The prompt will disappear once you register your program.
But if you choose not to register, that's OK too – just select Continue whenever the registration prompt appears.
This ensures we can contact you in the unlikely event of a program issue that affects your taxes, for example a calculation error. You can specify your contact preferences when you register.