I am working in a desktop version of TurboTax Business 2020. I have started a return but want to clear it and start over. How do I do this with the desktop version?

You can delete a tax return from within the TurboTax Windows Desktop Program on the very first screen after starting the program or go to File-Open. Click on the large square icon representing the file you wish to delete (avoid clicking the blue "Continue" button). Then just hit your delete key and answer the prompt.

OR Start the program and on the first page click the blue Find A Tax File link at the bottom of the box. Then in the list that pops up, you can right-click on the file and choose delete.

Or you can delete it from Windows.  The tax files end in .tax2020 and should be in your Documents folder and then in a Turbo Tax subfolder.

Or just start a new return, go to FILE - NEW, and ignore the wrong one.