How long has it been since you last accessed this account? If it hasn't been accessed in the last year, it may no longer be available:
- Inactive Account: After 270 days of inactivity, an Outlook.com (Hotmail, Live mail, MSN Mail) account becomes inactive, and any emails stored in the account are deleted.
- Deleted Account: After 365 days of inactivity, the account is permanently deleted.
- No Recovery: Once an account is deleted, it cannot be recovered, and any associated data is lost. A permanently deleted account cannot be re-used.
Your Microsoft account also has time limits: https://support.microsoft.com/en-us/topic/microsoft-account-activity-policy-7c0a9fa7-0982-b7c6-fd72-df852b63699f