if the optical or floppy drive is non-functional - this can be caused by a bad drive or by a bad (or loose) data cable.
Can you access the computer's BIOS and see if all drives are found?
A friend of mine brought his laptop over the other saying windows wouldn't start. I turned it on and immediately text starting flying down the screen followed by it running some test and then going to the windows startup screen, which shows the loading bar, but never went any further.
My initial though when any one gives me a computer to look at was virus, get to safe mode and go from there, well even though I got to the safe mode selection/start window that wouldn't start either.
Now I tried doing a windows restore but he never created a restore point so then I booted to his vista os disk and was going to do a repair from there but at no point would it see the hard drive. This leads me to believe the hard drive is shot and need replacing but I just thought I'd if anyone has any other ideas?