Everything you want, with one ID.
If you have a free Windows Live ID, there’s a lot you can do on Windows Phone 7, including backing up your phone to the Windows Live website so all your contacts, emails and calendars are up to date.
You can also track your phone if it’s lost or stolen and restore information if you get a new device.
You can stream all your photos to your phone and view them online, or if you’re into social networking, you can view all your social networking feeds in one place.
Windows Phone 7 allows you to connect with friends using your Xbox Live account, whether you want to play against friends, view your achievements or download new games. You’ll find all of this in the gaming hub.
You can sign up to a Windows Live ID on device or on a PC at www.live.com.
To sync your Windows Phone 7 with your PC, you can use Zune software.
Zune also allows you to explore the content of your phone, organise and play the music of your PC and download music if you have a Zune pass.