Use Linux tools. Harder to use, but does a better job than most commercial tools. How could it be unreadable? Just how old is your computer? Is it an MFF drive?!?! That’s what it would take to be unreadable. Or media damage...
As long as nothing is deleted from that hard drive or it is not formatted yet, there is still a chance to recover the data
And that’s a Hard, or destructive multi pass format. Linux tools have a good chance of recovering at least fragments if no such formatting was used.
Linux is an utter PITA too. So long as you use it how you're supposed to, it's great. But it's very unforgiving if you try and go out of the box. Like that time when I had to add a second monitor. Or recently when I tried to install webmin on archlinux... And don't get me started on Macs.
RIP. And I don't think think they're important enough to justify spending a few grand at drive savers right?
Well that's life. It decided that instead of giving you the lemons like a normal civilized person, it would go to your computer and squeeze it out all over your hard drive.