Hard Drive not Detecting

Hi,

My Dell Inspirion N5050 is not booting up, I ran the diagnosis on boot options F12 and here is it what I got message:

Hard drive 0-DST Short test
Test Result=Fail
Error code: 2000-0151
Validation: 15999
Message: hard drive 0 s/n 6VEYJGPG incorrect status = 3e

No Additional sense Information

Please assist me in this Regards

Thanks
Giridhar