Unable to access authentication phone

Question

My colleague cannot access her desktop computer as we have no password and the authentication mobile phone number is no longer in use.

Answer 1

If the computer and user account is organization-managed, the user should contact their IT administrator to reset the password or authentication methods.

For a personal Microsoft account, the account owner can select Reset Password or on the Windows sign-in screen or use Microsoft's official account recovery page. https://account.live.com/password/reset