If you haven't saved the income tax return just close the program. It will ask you if you want to save the income tax return and you say "No." Then start a new income tax return. You can create as many income tax returns as you like, though you can only e-file 5 of them.
If you've saved the income tax return somewhere along the line and you really want to "delete" it from your hard drive then use Microsoft File Explorer, navigate to the TurboTax folder under the Documents folder, select the file, right click and delete it.
Tom Young
