The thing with bad sectors is in the fact that once a HDD has bad sectors, you will probably want to replace it because using software won't do pretty much except mark those bad sectors as unavailable. But sooner or later, the drive will completely become inaccessible due to the fact that those marked portions will damage the drive even more.
I can recommend you SpinRite to test drive and see the results of the bad areas. Beside HDD information and diagnostics, you can also perform data recovery.
