Win XP scan disk

[BrenOS]

I have an external hdd that has some bad sectors on it I think. The windows based scan disk fails 20% through and doesn't fix anything. What's the best way to go about getting these bad sectors sorted? Do I need to do something in DOS or safe mode?

Thanks

 

[BrenOS]

The data is backed up that's no problem. I've formatted the drive and attempted to scan after that, it failed.

Surely I can tell it not to use the bad sectors but most of the drive is still ok?