Same problem TurboTax 2020 Premier...auto-update: initiates update, seems to download and then install which ends up as "Failed to install update. Microsoft Installer error: 1603, Fatal error during installation." So, went to manual update...worked fine. Then open TurboTax which of course checks for updates right away...cycle continues - same error as original attempt. This is not the first update I have run; also, have TT for Business 2020 installed on same machine - which is not encountering any issues.
