I am using a Lenovo ThinkPad Twist with Windows 8, and it isn't booting at all. It doesn't even show the Lenovo logo or anything. It makes no sound, nothing. It used to work. It stopped working after Action Center said to reboot because of a drive error. I rebooted the computer, but then my friend decided to randomly start typing on the keyboard and managed to cancel the shutdown. After that, it wouldn't log in so I held down the power button to force a shutdown. Now, it doesn't boot
This sometimes works with PC's and some laptops (don't know about ultrabooks without the ability to remove the batter). Hold the power button in for about 30 seconds. Release the button, take a deep breath, and try the power again. Good Luck!