Hello, thank you for reaching out to Microsoft Q&A.
May I please know when was the last time you were able to sign in with your Microsoft account successfully?
If you haven't signed in with your account for more than 2 years, your account will be put into an inactive state and will be closed.
(or) If your account is blocked due to violating Microsoft terms or unusual activity, you can try the account recovery form to recover your account.
Account Recovery form: https://account.live.com/acsr
Remember to use a familiar device from which you've frequently accessed your Microsoft account, as well as a familiar location. Microsoft will review your responses and respond within 24 hours. If you are verified, instructions on how to log back into your account will be sent to you, and if you are not verified, you will need to submit the Account Recovery form again. You can do this up to 2 times every 24 hours.
Alternatively, you can submit the Account reinstatement form to the Microsoft account digital safety team to review the reason your account was disabled and help with reinstatement, if possible.
https://www.microsoft.com/digitalsafety/account-reinstatement