Windows boot can't authenticate error, freezes

[Pixi3]

HP Envy m6, running windows 8 (side note, my system fan doesn't work, so I get the start up message "press enter to continue or system well shut down in 15 seconds"): turning my computer on it gives me a black screen with a blue box that says "Selected boot image did not authenticate. Press <Enter> to Continue." Pressing Enter turns off my computer. Turning it back on just gives me a blank screen, If left on nothing changes and it will continue to run the computer until the automatic shut off turns off my computer due to over heating.

I attempted "f2 on start up", but it brings up the "system not functioning" message again and freezes (pressing enter doesn't work) until the over heat auto shut down turns off the computer.

Attempted F11, same results as f2 attempt.

Any other suggestions? I would really like to use my computer

 

[Pixi3]

I tried the f2 and f11 solutions again, this time allowing both "cooling fan error" messages pop up, same results. Pressing the esc key does nothing, my computer still freezes on a blank screen and never makes it to the boot screen.