As Inventor 2020 is an older version, Autodesk has changed its licensing model from "Serial Number" to "Named User." If you are installing this on a fresh machine, you must ensure your Autodesk Account or Network License Server is configured to support legacy versions, or you may encounter activation errors.
If you missed the libraries during the initial install, you can add them without a full reinstall: Method A (Standard Libraries) autodesk inventor 2020 install
Before beginning the installation, ensure your system meets the requirements to run the software smoothly. As Inventor 2020 is an older version, Autodesk