Well it might be a BIOS problem, or a RAM problem, but the chances are overwhelmingly that it's a corrupt or dead drive.
Can you get into the BIOS before it checks for a HDD? If not, it may be a BIOS problem. Down load the latest BIOS from the makers support site and flash it. Low probability. Check your RAM, as a start remove and replace, again low probability.
If you can get into the BIOS, does the machine see the HDD? If so, it's not dead, see below. If no, it's dead, replace it.
If it does see the HDD, try booting with a boot floppy, you can download one from
here. If you can then access the drive and see your data files, back them up then reformat using FDISK and reload your OS and files from scratch.