Hotmail to Outlook.com upgrades: Your questions answered
If you click on the downward arrow in the top left hand corner of the Outlook.com home screen, a menu with four tabs should drop down.
Click on the one marked “People” and all of your old Hotmail contacts should be there. If that’s not the case, it might be worth flagging this issue to Microsoft to see if they can shed any light on it.
The People tab also lets you to populate your contacts list with details of your Facebook, Twitter and LinkedIn connections, and message their social networking profiles without leaving Outlook.