It's because alot of people have an a theory what way is the best to defrag. There is only one way to mark a bad sector.vern said:I asked almost the same question before but never got an answer. Something that would check disks like Norton DiskDoctor, chkdsk, or Scandisk. It is surprising that there aren't very many 3rd party disk checkers, but there are tons of defragging programs out there.