Sorry you can't. See this post,
https://ttlc.intuit.com/community/taxes/discussion/re-so-far-you-can-t-but-you-are-not-charged-for-t...
One user said…… The list of states that you used is stored on your computer. When you get a new computer it starts over with an empty list. Getting a new computer is the only way I know of to get rid of the unwanted states.
