There are normally 3 possible reasons for that error you have.
- BIOS Boot Order set to Boot to Network: Check BIOS settings for Boot Order.
- Check cable connections between Motherboard and Hard Drive.
- Failed Hard Drive.
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You can check the Hard Drive.
Go to your Computer Manufacturer's website > look for your Computer's specifications > find out brand of Hard Drive > go to Hard Drive Manufacturer's website > find and download Hard Drive Diagnostic software and make a Bootable disk from it on the Computer you are using to get here, following their instructions > test your Hard Drive to see if it has failed.
And you can also use this Method to test your Hard Drive:
"SeaTools for DOS"
http://www.seagate.com/support/downloads/seatools/
"SeaTools for DOS tutorial"