How do I use the turbo tax i purchased from costco
The instructions on how to download and install should have been with the purchase--either in the packet if bought in a store or in an email if purchased from Costco online. In any case, I assume you have the license code. See this FAQ:
You can go HERE to download the TurboTax Desktop Software. When you select the product, it will give you the option of Windows or MacOs for the operating system. During installation, you will be asked to enter your License Code that you purchased from Costco.
Please see these TurboTax Help Articles for more information: