This is part question and part response.
I'm not a Linux guy but I've used from it time to time.
Here is my case:
An HDD with Windows NTFS partition has failed, no recovery software on windows has got any data on it: no files, no partition, the disk fail to inactive.
Even the magical HDDRecovery software (I've used it many times with success) has got nothing many sector marked has
D (delay) and then nothing.
The first Linux attempt to recovery I've tried is booting with a Linux live CD Ubuntu Rescue Remix and tried to use
ddrescue -v -f /dev/sdc /mnt/sde1/image.img /mnt/sde1/log.txt
The command got an image file but unusable,
ddrescue says 1 error of 500gb (the whole disk size).
For a final attempt I've tried to boot up Puppylinux, and after a couple of mount error messages the disk is visible with all the files!?
I've started to copy and the files seems ok...
Anyone got similar results? Is
ddrescue the "final" rescue tool? or maybe not?