Need Advice On Data Recovery

1 drive
With Win 7
It was overwritten with Win XP
Then overwritten with Win 7
Then Upgraded (overwritten) with Win 10.

And you wish to retrieve, in toto, PDF docs from the original Win 7?
That's not gonna happen, no matter how much money you throw at it.

You might be able to retrieve some data, but you will probably need professional help. There are ways to read up to seven writes on a HDD. That's why a government secure wipe is 7 or more writes. A professional with the right equipment could possibly help you but will cost you a lot, I'm sure.

The reason why it can still "See" the files is because it is still picking up the MFT from the orginal windows 7. Just because it can SEE it doesn't mean it can recovery the files because they are stored elsewhere on the drive that is now more than likely been over written more times that any normal software recovery you can buy won't be able to recover. I know. i have 5 different kind of File Recovery tools my work uses and sometimes even after someone screwed up, deleted files, and before they realized it they deleted it and i ran every tool I had and it could see it but not recovery anything useful.

Even on one of my own hard drives a lot time ago, went to go make a RAID 1, (first time working with RAID) and it was all It will delete everything. i backed out of everything and it was just a RAW file system. I was unable to recovery any videos that were playable (I at least had a list of all of them) and most of my other stuff as well. Luckly back then is when all my important files like Documents were synced between my Laptop and PC so that wasn't a huge deal.

But if you EVER delete a file or format something the LAST thing you EVER do is either format it, write a files, startup windows, etc. You hold the power button, shut that down, yank out the drink, and plug it into another PC. Even then I always make a bit for bit image of the drive and do recovery of that imaged drive to prevent any kind of damage to the original drive. File recovery can work when used right or you can screw it up even more.

There is still a chance that a data recovery company would be helpful. You would need to be specific with them which files you need so that you and they can judge success in this situation. Or you can keep trying more software tools as I'd think they'd have some success.

Like others have said, with an OS reinstall, it only writes to the space needed for the fresh install. It is unknown how much of the previous data is there still waiting in the free space. You can't be guaranteed of anything, but there is likely significant data to be recovered. The more you use and write to the drive, the more chance you are permanently overwriting the previous data that was there in the free space. But even multiple OS reinstalls have a limited effect. What would be much worse is writing a large amount of data over the entire drive.

Data recovery companies have lots of different software (of course including free and paid) and they know how to use them best in each situation. Sometimes with overwrite damage like this, they can even partially recover the file tables from the previous OS installation to help recovering the missing data, also maintaining file names and directory structure. Other times, with too much damage, raw recovery is the best - they will just get the most files possible through file signature recognition, with correct extensions, but with no file names.

I would not give up hope. Also your privacy concerns would not be an issue with a reputable data recovery company that has confidentiality. And for the cost concern, lots of companies will do a free evaluation so you won't be obligated to pay until you know what the recovery cost would be and you choose to go forward. Most also do not charge if they are not successful.

Or you can keep trying software yourself. It seems like Recuva is always mentioned, but there are better options particularly for something like this. R-Studio or ReclaiMe or two off the top of my head. Buying lots of different software could end up approaching what professional recovery would cost though, and you'd be missing the professional's skill and experience.

Good luck!