Bartrum //There are certain files stored on a hard drive that have to be in a certain sector of the disk (The boot sector) if this sector becomes bad the whole disk will become unusable, these files cannot be moved to another sector so while windows may detect an error it can do nothing about it.//
I'm not sure that's completely correct. In the days when I ran an IBM system every disc had spare blocks on the outside. A sector is a string of blocks, initially contiguous. Each block on a disc has a pointer to the next block in the series so, if a block has problems, the system modifies the block BEFORE that one and points it to a spare block; the spare block is given a pointer to the block AFTER the bad block. Thus the bad block is removed from the sector and replaced by a good one; the sector is solid again. I see no reason why this system, in use in the 1970s, should be changed at all.