Remove any floppy disks or CD-ROMs from the system & restart the system.
Check if the Hard-disk drive is detected in the CMOS.
Boot to the DOS prompt using a bootable floppy or CD. (Recovery Console in case of Windows XP/2000) & use the command FDISK /mbr or fixmbr.
Reseat the Hard drive. If issue remains, replace the Hard disk drive.
