Aurora r4 boot help

When I start the computer, it stays at a black screen with a blinking cursor. I tried the steps outlined in the video, but when trying to open the boot menu I have trouble. For some odd reason, the loading screen zips by without giving me a chance to open the boot menu-I even tried mashing f12 until it worked. I really just want to know if there is an easier way to access the boot from the black screen or some other method that might help.