i recently performed a system restore on my hp windows 8 laptop while connected to a monitor because the screen is broken, and afterwords the computer would not connect to the monitor so im thinking it isnt booting at all. i tried pressing f11 a bunch of times but it only connects to the monitor for noigh time for the green light to come on and thats it. i tried the unplugging the battery thing and power cord and holding the power button for 15-30 seconds however i have the same result.
The Windows update software does not seem to understand connecting to an external monitor. As you have found out it's often fatal to update with a broken laptop screen. Perhaps replacing the screen is your only option.