Laptop is not starting.

Hi,

I am using Dell Inspiron 5520. It is not starting. I've run the diagnostic test to check for errors. It is showing the following.

Error code: 2000-0142

Validation: 97075

Msg: Hard drive 0 - S/N S2X1JA0C852569, short self test unsuccessful.

What should I do now ?

Regards,

Ravi Kiran.