How to access the boot menu on a Lenovo g50?

My Lenovo g50 is stuck on a screen that says, "We couldn't complete the updates Undoing changes Don't turn off your computer." How do I access the boot menu so I can restore it? I try pressing fn+f8 but it doesn't work.

Guest

Usually you need to repeatly and rapidly hit either F2, F8, F10 or delete during start up to enter the boot menu. The options should show up on the screen during start up.

craze

Ok seems like its windows 8, f12 is the button to get an boot menu.

but leave the computer running for while it will revert back all.

if not this is try each button's all time. ESC, F1, F2, then F11, F12.

Guest

Press function key + f12

Guest