While Updating phone from Windows 8.1 to Windows 10, why does my phone restart every minute?

[Ratan Brahmanya]

While Updating phone from windows 8.1 to Windows 10 My Phone Restart

While i was updating my phone from Windows 8.1 to windows 10. All Download & Installed completed then While Booting Again to Install OS ( 2 Gear Rotate ) it Restarts after every 1 min and Progress bar is not filling.