Windows reset not working

Hi,
My friend gave me his old Asus laptop, which had been upgraded from Win 7 to Win 10 a while back.
The windows version is 1809
Installed on 2019-4-17
OS build : 17763.1039

I would like to remove all of his personal information, so I tried :
Start > Settings > Update & security > Recovery, and chose to remove all files, but that didn’t work. I get a message that the reset could not be completed.

So I have 2 questions :
- Is there another way to reset windows 10 so that no personal files or data is retained ?
- if not, can I just buy another Windows 10 license and install it over the current one, and what are the caveats ?

You can boot your computer with Windows 10 installation media and delete all partitions to install Windows 10 this will delete all data on the drive.

You can create Windows 10 installation media with Media Creation Tool.

https://www.microsoft.com/en-us/software-download/windows10

https://www.nirsoft.net/utils/produc...ey_viewer.html

See this tutorial on clean install:

Clean Install Windows 10

Clean install is the way to go - make a full system backup and archive it when done

It works !!
Problem solved, thanks