Not answering your question, but some advice re backups.
Never leave yourself in a situation where the only copy of a picture is on your hard disk, in case the computer or hard disk crashes.
I do the following:
1) Download the pictures from my camera to hard disk, BUT LEAVE THEM ON MY CAMERA in case PC fails.
2) Back-up the pictures from your hard disk to a CD or DVD (I do it on 2 copies in case one fails)
3) If you can, check the pictures on the CD or DVD can be viewed OK on another computer
4) Once you know you have them safely backup up to CD or DVD then you can delete them from the camera.
Now even if you PC or hard disk crashes you know you have them safely backed up.
If you follow this process you should never have a problem with losing pictures.