To activate TurboTax after download, first install the software by double-clicking the downloaded setup file and following the on-screen instructions. Once installed, open TurboTax. Youll be prompted to enter your license code to activate the product. Make sure you have your 16-character code ready. If you purchased a physical copy, the code is inside the box. For digital purchases, its in your confirmation email. Visit www.installturbotax.com with license code to enter the code and complete activation. After entering the code, click Continue to finish setup and start filing your taxes with TurboTax. Activation is quick and essential for full access.