To download the TurboTax 2025 install file, start by visiting the official website at installturbotax.com. Sign in using your Intuit account credentials. Once logged in, navigate to the Downloads section and locate TurboTax 2025. Select the version you purchased and click the download button. Save the install file to your computer. After the download completes, double-click the file to start the installation process. Follow the on-screen instructions to complete setup. Ensure your system meets the minimum requirements for smooth installation.