Ok, I am glad it gives you a key in return. That's good news. It means the motherboard itself has an OEM license onboard. Somehow the previous user must have upgraded it to enterprise using an eval license.
You will have to backup all of your personal files. Then perform a clean install to use the onboard license. It might be for Home or Pro, we don't know. But the clean install will pick up the license automatically and install what the license is for without asking you to input key or choose edition.
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...
Run the tool and select "Create installation media for another PC."
Choose your language, edition, and architecture (32 or 64-bit) and select "Next."
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 10, 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 10 on your computer.