When you’re composing or forwarding an email, Outlook.com shows your most frequent contacts. To see your full contact list, click To—it's above the box where your contacts appear.
To manage your contacts, go to the People page
If you're in Outlook.com
Click the arrow next to the Outlook logo in the upper left.
If you still can't see all your contacts, click the Options icon on the People page
and make sure all your social networks are selected.
If you're not in Outlook.com
Go to people.live.com and sign in with your Microsoft account.