unable to log on with PIN since backup phone number is a now non-existent land line

What is happening matches a Microsoft account verification problem, not a Windows PIN-only problem. The practical path is to recover or replace the account security info first, then reset the PIN.

1. On the Windows sign-in screen, check whether Sign-in options allows Password instead of PIN.
   • If the account password works, sign in that way first.
   • After reaching the desktop, go to Settings > Accounts > Sign-in options > PIN (Windows Hello) and reset or create a new PIN.
2. If password sign-in is blocked because verification is still being sent to the old landline, select I don’t have any of these on the verification screen.
   • This starts the process to replace the old security information.
   • If all old security info is replaced, the account can be restricted for 30 days before the new security info becomes usable.
3. If the listed phone number is a landline, that explains part of the failure.
   • Microsoft states verification codes can be sent to a phone that receives text messages and it does not need to already be associated with the account.
   • A VOIP number cannot be added for sign-in or verification codes.
   • If online account unlock is offered, use a mobile number that can receive SMS.
4. Since ACSR was already tried, use the recovery path only for account recovery, not as a PIN reset shortcut.
   • The recovery form can be completed with a contact email that is accessible.
   • If possible, complete it from a device and location previously used for that account.
   • If two-step verification is enabled and there is no access to any alternate verification method, support cannot bypass that by sending reset links or changing account details.
5. If verification attempts are being blocked or codes are not arriving:
   • Do not keep making repeated requests.
   • Try another verification method if one exists.
   • Try another network, such as switching between Wi‑Fi and cellular.
   • Wait at least 24 hours before retrying; if still blocked, wait longer, up to 1 week.
6. If the immediate goal is simply to get the PC usable again, and there is no working password sign-in and no accessible verification method, the only fast device-side workaround mentioned is a factory reset from WinRE and signing in with a different account.
   • Warning: this is disruptive and can risk data loss if files are not backed up.
7. For guided recovery, use Microsoft’s sign-in helper, which is the recommended path for most sign-in issues.

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