Did you lose power or turn off whilst updating? That sort of thing might cause the software to corrupt and get stuck in a loop or endless update.
Disc drive shoudln't have anything to do with it, but it might. You never know nowadays.
If it won't stop the update process try to hard reset it (hold down power button for 5 sec) or disconnect power completely. Maybe unplugging the network cable might help.
If everything fails you might want to look into factory resetting your Xbox. Take note that you'll lose all saved data in the internal HDD in the process of this. Only use this as a last resort.