Windows Live ID from Microsoft.

A Microsoft account or MSA (previously known as Microsoft Passport, .NET Passport, Microsoft Passport Network, and Windows Live ID) is a single sign-on Microsoft user account for Microsoft customers to log in to Microsoft services (like Outlook)...

Windows Live® ID, also known as a Microsoft® account, allows users to log in to Microsoft® websites, services and properties using an email address and password. This is great for those who want easy...

Your Windows Live ID is the email address and password you used to create your gamertag. When you sign in to your phone using that ID, you get your gamerscore, avatar and all your achievements on...