Hello and welcome to the forum.
How did you perform the upgrade?
Make sure there are no USB peripherals plugged into your computer including SD cards and the like.
Some third party security suites seem to be causing some issues with the upgrade process (downloading, installing, post installation, etc.,) If you have things like Norton, McAfees, AVG, Comodo, ZoneAlarm, etc., etc., etc.
Consider removing them completely including after the uninstall, running the vendor specific proprietary removal tool (google it for your specific product).