Sign out of Xbox Live, and then sign in to Xbox Live again. Your friends list should now appear in the Xbox Dashboard.
The Xbox 360 console lets you customize and manage your family's access to games, movies, and television content. Learn more about the Xbox 360 parental controls.
My console randomly restarts
Make sure that the Guide button on the controller and the power button on the console are not pressed or stuck, and then restart the console. If these buttons are pressed, they may cause the console to restart.
Turn off the console.
If you use the Xbox 360 Hard Drive, verify that it is connected correctly. In rare instances, if the Xbox 360 Hard Drive is not attached correctly, the Xbox 360 console may restart over and over for no apparent reason. For more information on how to reseat the Xbox 360 Hard Drive, see Add or remove an Xbox 360 Hard Drive.