Hello @help_laptops
Welcome to the HP Support forum.
Based on the provided information, your PC is HP Stream 11-r010nr / netbook/ultrabook and comes with Windows 10.
I understand that you were using Windows 10 fully updated but you wanted to reset your PC. The process obviously has failed because now you cannot start the PC.
I suggest you restart the process but this time, please monitor it - here is how:
1. Please, shutdown the computer using the power button
2. Power it on.
2.1 As soon as you press the power-on button, before seeing any logos, immediately begin hitting the Esc button (like tap-tap-tap).
This should open a HP Startup Menu which may look similar to this one

3. Choose F11 for System Recovery options.
The computer should boot from it's recovery partition to open you various recovery options. Note, that F11 option will only work if the recovery partition is there (not deleted) and intact. From there, you have prenty of options to choose from.
4. Go to Troubleshoot and select either "HP Recovery" / "HP Recovery Manager"
or "Reset this PC" option - whatever is available on your model
5. Monitor the process and hopefully this will it will complete.
If it does not complete, you will need to check the hardware for any issues and use original HP recovery media to restore the operating system. But if this is needed, I will provide you with specific steps later.
Looking forward to your reply and update 🙂
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*** HP employee *** I express personal opinion only *** Joined the Community in 2013