Hello, this is Emily.
If the initial set up was interrupted, it can cause corruption. From what you described, it looks like the user profile wasn't established successfully and it is now corrupted. I will recommend that you start over.
See if this can work. On the sign on page, click on the power icon on the lower right, then hold down Shift key while you click on Restart. Then choose Troubleshoot > Reset this PC. And choose the option that deletes everything. Then start over.
If the reset won't work for some reason, you will need to do a clean install. I am assuming this is Windows 11? To perform a clean installation of Windows 11 using the Windows Media Creation Tool:
The following steps should be done on a working Windows computer:
Download the Windows Media Creation Tool from Microsoft's official website. https://www.microsoft.com/software-download/win... click on the "download now" button under "Create Windows 11 Installation Media"
Run the tool and select "Create installation media for another PC."
Choose "USB flash drive" as the media to use for the installation and select "Next."
Connect a USB flash drive with at least 8 GB of free space to your computer.
Select the USB flash drive you want to use, and then select "Next."
The tool will then download the required files and create the installation media.
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Now these steps will be done on your problematic computer:
Go to the computer's BIOS boot menu to have it boot from the USB drive.
Follow the on-screen instructions to install Windows 11, making sure to choose "Custom install" and select the option to delete all existing partitions.
Once the installation is complete, you'll have a clean installation of Windows 11 on your computer.
Also, if your son is in your family safety group, it is best that the initial user is set up as the family organizer's account, then go to Settings > Accounts > Family, next to the son's email, choose "allow sign in". Do not set any family member's account as the initial user.