Laptop Questions? Ask a Laptop Technician for Answers ASAP!
The Windows 10 upgrade takes a very long time to install.
If the upgrade was interrupted or did not complete for some reason, it will become corrupted and the laptop will not start up correctly.
If Windows is not starting up then you will need to try using the built-in recovery manager:
When the laptop is starting up, keep tapping the F11 key to launch the recovery manager and follow the on-screen instructions to recover your laptop.