ubuntu likes playing up when it comes to rebooting.
make sure everything is set in the bios the way it was before it started playing up, and also, make sure the drive has been shut down cleanly. then, if it boots, hit boot in recovery mode.
make sure everything is set in the bios the way it was before it started playing up, and also, make sure the drive has been shut down cleanly. then, if it boots, hit boot in recovery mode.