That would not be considered an upgrade as it is a different version of the software. You would need to purchase the download version please note that it is only good for Windows computers and no mac.
I purchased the online version at a retail store and was assured by them that I could download the desktop version. Clearly this is not true. I have not activated my online version, yet I appear to be able to start a new return. I have definitely NOT started a return so is there anything you can do at your end?