If you do not need the contents on your harddrive, you may fix the bad sector by writing zeroes to every sector on the drive. You can do this in Linux or with special Windows utilities. Windows 7 can also do a full format that writes zeroes. Vista and lower do not write zeroes to every sector when formatting.
After zero-writing, check the drive's SMART data:
- CURRENT_PENDING_SECTOR (unfixed bad sectors; should be zero)
- REALLOCATED_SECTOR_COUNT (fixed bad sectors that no longer cause problems)