Using Classic Outlook on Windows for personal email, calendar, and contact management
Hi STUART PARSONAGE,
Since you can sign in to one account normally, while the problem repeatedly affects only the other account, it would be helpful to determine whether the failure is happening at the Microsoft account level or only within classic Outlook.
Please try signing in to the affected account directly at Outlook.com using a private browser window. If that also fails, please share the exact error message or error code shown after entering the new password, and let me know whether the error appears before or after the verification step. You may post a screenshot, but please hide the full email address, verification codes, and recovery details.
If the account works on Outlook.com but not in classic Outlook, close Outlook, open Control Panel > Credential Manager > Windows Credentials, and remove only the saved Microsoft Office or Outlook credentials associated with the affected account. Then restart the computer and add the account to Outlook again.
As the password has already been reset successfully, I would avoid repeating another reset for now. Instead, run the Microsoft account Sign-in Helper with the affected address, as it checks that specific account and provides the relevant path based on its current sign-in status.
Please also confirm whether both accounts are personal Outlook.com accounts, and whether the same failure occurs on another browser or device. These details will help separate an account-specific restriction from a locally cached Outlook sign-in problem. Thank you so much for your understanding.
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