I have tried all of that, more than once, with no success. I created a new window users account, and moved all my files and settings, which took some hours to do, but encountered the same problem eventually. Quickbooks worked on the new account at first, but quit later. I then upgraded to Quickbooks 2021, in the desperate hope that that might cure this, but alas, $200 later it did not. Quickbooks 2021 Pro Plus worked when I first installed it, but once it did all of the updates it now just crashes back to the desktop, with no error messages, just a few seconds after launching. It never even lets me pick which company file to open.