In your initial post, you said you upgraded from Ubuntu 10 but did not indicate if it was 10.04 or 10.10 and you still haven't responded to that. You should be able to upgrade from 10.04 to 12.04 per the Ubuntu site but will likely have problems going from 10.10 to 12.04 as you would need to upgrade by steps of each version.
You also did not answer whether there were any hardware changes or any software changes after the first reboot?
Its showing GFenetic and Recovery mode for ever.
So what happens when you highlight either choice and hit the Enter key?