Once you reconnect, you can chat with your Facebook friends, see their latest updates, share files, and more. Your Facebook connection is available in places where you sign in with your Microsoft account, including Windows 8, Windows Phone, Outlook.com, OneDrive, and Office 2013.
What happened?
You might have changed your password on Facebook or changed your Facebook privacy settings in a way that broke the connection. When you reconnect to Facebook, your connection settings will be restored.
Thanks for using your Microsoft account to bring the people who matter most together in one place. You can change your connection settings anytime and find more ways to connect at https://profile.live.com/services.