So long as any cd or dvd left inside the drive is not a bootable disk,the comp will go to the next boot device automatically after x amount of seconds.so if you set dvd drive as first boot priority,the hdd as the second that is the order they will boot in,to me that's normal as i have floppy as first,dvd as second & hdd as last. As for the black screen you mean there is wording at the bottom saying HP,along with f8 or f10 or something like that,go back into BIOS make sure the hdd is enabled,there's also a setting in the BIOS that can let you see your hardware as it gets detected while in that black screen unfortunately i can't remember the name of it,as hardware is detected it will list ram,hdd,floppy & dvd drives,the vacant black screen you describes almost sounds like there's no hdd
