I'm not exactly sure at what point your TurboTax Free Edition was "registered". But I do know that registering or making any type of payment prevents a user from clearing the return.
That said, you can simply abandon your return. There's no need to delete all of your information. You can log back in at any time to complete your e-filing. If you decide you don't want to file this return, you can just leave it on the secure TurboTax servers.
*** I am NOT a tax expert. I am a seasoned TurboTax user, and volunteer to provide assistance to TT users. Nothing I post is to be considered TAX ADVICE; I bear no legal liability for responses.***
