Amazon Fire TV 1st Generation User Manual page 39

Amazon Account
If your device is already registered to your Amazon account, you'll see a Deregister option you can use to
remove it from your account. Once you deregister, you're prompted to Register again to connect your
device to an Amazon account. For more information, go to Register or Deregister Your Amazon Fire TV
Device.
Sync Amazon Content
Select this option to make sure your latest content purchases from Amazon are available on your Fire TV.
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