To import contacts into an Outlook.com account:
Go to the top left of your inbox, click the arrow, and select People:
On your People screen click the option to import from a file:
Select Microsoft Outlook (CSV), browse to the file exported from Yahoo, and click Import:
Continue through the wizard and remove duplicate contacts, or return to Outlook.com by clicking the arrow near the top left:
Go to the top left of your inbox, click the arrow, and select People:
On your People screen click the option to import from a file:
Select Microsoft Outlook (CSV), browse to the file exported from Yahoo, and click Import:
Continue through the wizard and remove duplicate contacts, or return to Outlook.com by clicking the arrow near the top left: