Wait let me clarify.
bad sectors can not be fixed by windows. It can only be fixed with a app called
HDD Regenerator ,, I payed for it 15 bucks. You run that and next time you do chkdsk you will see it says 0 bad seconds your percantage healthy will go up too.
...but if the sectors went bad, you're just getting a false sense of security. Of course Windows doesn't fix bad sectors. It marks them, and keeps a table of them as places not to write to. The hardware is what should handle them. It tries, and usually succeeds, keeping your DATA safe even when the drive is failing, by trying over and over again, then writing the data somewhere else.
Some programs like that can help repair partition and FS problems, when a bad sector unexpectedly eats data, but the best fix is to take an increase in bad sectors as an indicator that the drive should be replaced, and/or that something else in the system is faulty (such as PSU or RAM, or around here, a too-high OC).
If you must
recover the data, and dd doesn't cut it, then by all means, spend the money. But, the rest is just marketing, often deceptive, 99% of the time. If a re-write and remarking "fix" the problem sectors now, whatever caused them in the first place has still not been fixed.