If you have a Windows computer and it forced you to make a Microsoft account to log in to it, here’s how to switch that account to a local one: https://web.archive.org/web/20240612104753/https:/support.microsoft.com/en-us/windows/change-from-a-local-account-to-a-microsoft-account-395203bf-9f1b-eb24-b042-5b8dae6c1d20
This used to be in the Microsoft support docs, but at some point last year they removed it. Thank you, Wayback Machine!