Actually it's better to use the download method. There should be instructions with the CD on how to download it instead. In fact this link says you can't use both the CD and download.
How to download Turbo Tax instead of using the CD
https://ttlc.intuit.com/community/installing/help/i-bought-the-cd-but-my-computer-doesn-t-have-a-cd-drive/00/26450