You can buy and download online.
You can purchase the desktop version as a download directly from TurboTax here.
https://turbotax.intuit.com/personal-taxes/cd-download/
Choose which edition you want and click the BUY NOW button. On the popup, then be sure you specify the correct operating system you want for the download--Mac or Windows PC.
NOTE: The Basic Edition does not have a state program and cannot import from ItsDeductible.
After purchasing, you can retrieve your download here:
https://shop.turbotax.intuit.com/commerce/account/secure/login.jsp?pagecontext=download
