Error code =2000-0142

Hi guys.

3 days back wen i started my laptop it startd saying "launch repair " or

Start windows normally. I tried both but it loops back to same place..

I noticed a blue screen inbetween. Then i pressed F8 and entered option saying

Dont shutdown even in blue screen....it was written UNMOUNTABLE BOOT VOLUME

then i ran diagnostics i got an error code =2000-0142, validation =49064,msg-hard drivr 0- S/N J 2540054DGU5SE,self test unsuccessful, status = 7

I started my laptop with a recovery disc.i tried restoring it to factory settings..it was showing RECOVERY PROCESS FAILED. No enough SPACE IN DRIVE..

plz help i have tried even opening up d laptop chechking d hard drive connections

It sounds good....its an N5110 dell laptop i boight 3 years back..