Hi. My name is***** you for your question and the opportunity to assist.
Are you unable to log in to you new PC using your Yahoo! email address?
Thank you. Is this a Windows 10 computer?
Since this is a new computer would it be OK to reset it and you could
start over fresh?
Reset, meaning a re-install of Windows where you would set it up again just like when you first turned it on.
I'll forward your request to customer service.