Hard disk suddenly becomes unreadable

[surenther.ss]

Friends i have 2 hard disk 40 gb and 160gb....suddenly i dont why..my system hangs and all those partitions of 160gb hard disk goes off from my computer..i mean the 160gb harddisk becomes unreadable

Please help

 

[aditya1987]

Does it show S.M.A.R.T error before bios screen?

You can also do surface test of you HDD with Partiton Table Doctor (PTD)