I'm have finished building my first pc today and every time I try to boot up it keeps coming up with reboot and select boot drive I have tried to fix this myself by googling it and my problem seem a bot unique as I am unable to get into the bios as the screen for that is on on screen for a split second and if I do press the button in time it just takes me to a black screen with a little white dash in the top left corner please help me!! Thanks