Hey, it is possible there is a disk-boot configuration problem. The problem is that the computer has not been given anything to boot or it does not see anything to boot.
Give this a try: In your bios go to your boot configuration and just look at your boot devices your hard disk might be set to disabled and that is causing the comp not to see it and therefore cannot boot it, if that is the case enable it.
Also, if you have 1 or more hard disks in your comp make sure you have the disk you have your os on set to the primary disk. and then in the boot priority part of your bios place your hard disk as the first bootable device and then your other hard disk and dvd etc.
If all that fails it is either a broken hard drive ( i suggest trying it in another comp to make sure) or a faulty ide or sata controller.
I hope this helps.