I interrupted my 14.04 (from 13.10) upgrade because my computer froze. So i could not boot into Ubuntu. Using Live CD, I tried a guide online to fix. http://ubuntuforums.org/showthread.php?t=1920317

The thing is, when i rebooted my computer after upgrading, I cannot enter boot screen. After Grub, selecting normal boot puts me in a empty screen with a blinking underscore for a long time. Trying failsafe graphics mode does not work. It sends me back to recovery screen.