|Check your hard drive with the manufacturer's diagnostics.|
See the latter part of response 1 in this:
(thanks to Dan Penny for this link:)
Hard Drive Diagnostics Tools and Utilities
If you don't have a floppy drive, you can get a CD image diagnostic utility from most hard drive manufacturer's web sites, but obviously you would need to make a burned CD, preferably a CD-R for best compatibilty, on another computer if you need to.
If the hard drive itself tests okay, any data problems found can be fixed, one way or another.
See A side note below for a possible cause of your problem.
If hard drive itself does NOT test okay....
All modern hard drives have automatic harware routines that swap bad sectors with spare good ones when the drive routines encounter new bad sectors. The fact that the operating system is "seeing" any "visible" to it bad sectors at all indicates the spare good sectors have probably been used up - your drive is probably failing.
- if the diagnostics quit, say, after 99 bad sectors are found, your drive is failing and nothing can be done to fix the bad sectors. You could try connecting the drive to another working computer if you want to copy data you don't want to lose off of it, but you need another hard drive
- if the diagnostics complete and say you have bad sectors, that indicates it detected fewer bad sectors than a threshold number that if exceeded will cause the diagnostics to quit - you can usually try having the diagnostics zero fill the drive or similar to try to fix the problem - that MAY get rid of the bad sectors - BUT you need to copy all the data on the drive to somewhere else BEFORE you zero fill the drive, and even if that's sucessful, and you copy your data back to the drive and it works fine, it's quite likely the drive will eventually develop visible to the operating system bad sectors again.
A side note.
If you copy the data on an entire partition, or the data on an entire drive, if the operating system on the partition or drive you copied was finding "visible" to it bad sectors, the operating system's bad sector location info is copied to the destination location as well. It can be difficult or impossible to get rid of the false bad sector info on the destination location. E.g. it's difficult to fix that problem in XP and below, you have to use third party prgramsto fix that, but that can be fixed in Vista and probably Windows 7.