When you turn on a brand new Windows Phone for the first time, you will be prompted to create a Microsoft Account on it. [See the article entitled, “What is a Microsoft Account?” to learn about the fundamental ways that the Microsoft Account is used on a windows phone.]
If you already have a Microsoft-related account that you use, you don’t need to create a new account. You can use the username (which is an email address) and password of your preferred Microsoft-related account when you create the Microsoft Account on the phone.
When you create the Microsoft Account on the phone, you may notice that the only data that can be selected to sync under the “Content to sync” heading is Email, but if you set up a secondary hotmail.com, live.com, or outlook.com account on the phone, you will find options to sync Email, Contacts, Calendar, and Tasks under the “Content to sync” heading.