i am just a beginner and so 0 posts...
But surely he would have had a post count of at least 1?
this term "back setters" came to me form a local service person.
Possibly you mis-heard him. It seemed previously that he may have been saying (or meaning to say) "bad sectors".
he told me that my hdd will soon fail..reason: "due to frequent formatting of the hard disk a lot of back setters are created and this is harmful for the hdd"
Now we are certain he meant "bad sectors", since they are detected (not "created") during formatting. Your hard disk may or may not be failing, but if it is failing, formatting did not cause it.
...honestly i dont know what he meant
When you format a hard disk, any bad sectors are detected and marked so they are not used. To find a few is normal. No hard disk is perfect. If the format process finds a large number of bad sectors this may be a sign of disk trouble, but it is not caused by the format.
Is your hard disk showing signs of trouble?