How to Repair a Bad Sector
Now, first of all, I remind you again that in case your bad sectors are the result of some physical damage, this can't be repaired, you won't have your sector back. But as we discussed above, you can 'cheat' and mark that sector as unusable and then the operating system will ignore it.
Since I have no idea what operating system are you using, I will try to generalize the fixing process.
1: Open up Windows Explorer or My Computer so you can see your partitions. Right Click one and select Properties.
2: Click on the Tools tab, you will see Error-checking, Defragmentation and Backup on the most modern systems. What we need is Error-checking.
3: If you are running Vista or Windows 7, and you probably are, check both options - Automatically fix file system errors and Scan for and attempt recovery of bad sectors. Now run the scanner.
Manually this can be done from the Command Prompt with the CHKDSK and I suggest you to run it with the 'R' attribute, in other words CHKDSK /r.
This is also not the very best method to get things done. However, the other techniques require you to be generally more experienced. When you mess up with hard drives, sectors, clusters and partitions things can go bad really easily.