When updates for your Windows Phone 7 are available, you'll see a prompt on your phone. You'll need to use the Zune Music + Video software to install updates.
To install an update for your Windows Phone 7
Start the Zune Music + Video software.
Connect your phone to your PC with a USB cable.
When Zune prompts you to install updates, click Update Now and follow the on-screen instructions.
You can also check for updates by going to Settings, Phone, Update. If an update is available, click Update.
Note
You must have the latest version of the Zune software before you can update your Windows Phone 7. If an update is available for the Zune software, you will be prompted to update it before you can update your phone.
