This a PC Tips for fixing a bad sector on your harddisk :
1: Double-click on “My Computer”.
2: Select the disk/partition that you want to diagnose and repair.
3: Right click on the disk/partition you selected and click on “Properties”
4: Choose the “Tools” tab.
5: Click the “Check Now” button under “Error Checking Status”.
6: Depending on your type of Windows, choose “Thorough” or “Scan for and Attempt Recovery of Bad Sectors.”
7: Click Start.