If the magnetic layer of the hard drive got disrupted then the format MAY repair this, it is iffy though.
If it is that the areas of the hard drive have seen a lot of use from certain areas being used a lot of times then the hard drive platters are basically burned out and there is no fixing that kind of damage. Also if there has been a head crash or even small amounts of dust got between the platter and the read/write head the hard drive is not fixable. And if you dropped your computer or jolted it hard, then you may have damaged the hard drive whether the computer was on or not.
I'm totally with voyagerfan99. Its just better to replace the drive. Why take a chance on something like this when they are so cheap?