If the computer was set up with a Microsoft Account it will be on one of their servers. One of these pages will have help on changing it:
DuckDuckGo. Privacy, Simplified.
duckduckgo.com
I've had success in while logged in with Administrative rights to create a new User with a slightly different name such as Rich or Richard instead of Dick and the correct/desired information, reboot and log in as the new User then remove the old one taking possession of the data/files.