this dose not alway mean that harddisk is gone
since u have backed up the data
u can download hdd scaning utility from your hdd manufacture
in 99% of that software recovers the hdd as in service centers the do
this step first (as 99% of hdd problems could be corrected through s/w )
if that dose do u the good
take it to service center and they will give u the refurbrished one (they will tk atleat 2 weeks )