Hi, I'm Bernard, a fellow Windows user. I'm happy to help!
If the account is locked for more than 30 days, I recommend following the steps below:
Method 1. Recover a Microsoft account by resetting the password:
Go to this link: https://go.microsoft.com/fwlink/?linkid=2273955 and follow the prompt to reset the password.
For reference: https://support.microsoft.com/ja-jp/account-billing/%E5%BF%98%E3%82%8C%E3%81%A6%E3%81%97%E3%81%BE%E3%81%A3%E3%81%9F-microsoft-%E3%82%A2%E3%82%AB%E3%82%A6%E3%83%B3%E3%83%88%E3%81%AE%E3%83%91%E3%82%B9%E3%83%AF%E3%83%BC%E3%83%89%E3%82%92%E3%83%AA%E3%82%BB%E3%83%83%E3%83%88%E3%81%99%E3%82%8B-eff4f067-5042-c1a3-fe72-b04d60556c37
Method 2. If you cannot reset the password or are unable to verify the account, I recommend submitting a recovery form:
https://account.live.com/acsr
Fill up the form and wait for the reply within 2-3 days.
Please complete the form and expect a reply within a couple of days.