Computer Secondary Memory Is Halted

Many Computer contains a lot of data of hard disk. Its strongly recommended that every computer works as his processor speed. But in this step Over loaded hard disk is not matter for working computer. But I have a problem that have been suffering many times that hard disk drive is not working suddenly. After a lot of trying the result is zero, my all drive becomes un partitioned and also unallocated. Again I have created partitioned and again appearing this problem. How it was happened and how I will solve it?

