The first thing you need to do is to copy all irreplaceable data to another drive or optical disks, if you haven't done so already. Bad sectors don't get fixed. They get marked as bad so they no longer get written to. A few bad sectors isn't much of an issue, but if they continue to increase, the drive will need to be replaced. Run WD's diagnostic software. If you don't understand the results, post them here and someone can explain them to you.