Formatted Windows 10 partition by mistake while installing Ubuntu. How can I recover it?

I wanted to create dual boot machine with Windows 10 and Ubuntu 14.04.3 LTS but something went wrong and I accidentally formatted Windows partition. After formatting, I cancelled installation. I didn't click on "Install" and so I think that data hasn't been overwritten. So, how can I recover the partition with all data (if possible)?

I need this data badly as I don't have, unfortunately, a backup for them.

I'm trying to use TestDisk on Ubuntu liveCD but I don't want to make another mistake. What do I have to do now?

I'm at this point:

HPFS - NTFS [OS] and HPFS - NTFS [DATA] should be the old partitions of Windows (C: and D:). If I select the first one and press P the terminal crashes, but if I do the same with both NTFS [DATA] partitions it shows me the list of a part of my files. But now I don't know how to proceed...

Solution 1:

It's extremely unlikely that you'll recover a fully working Windows installation. Although you haven't written any files to your Linux partitions, their mere existence means that you've overwritten parts of the original partitions, irretrievably replacing some data on them. If you're very very very VERY lucky, nothing important will have been lost; but chances are at least one or two critical boot files is now toast. If you're merely very very lucky, TestDisk might recover the partition in an intact-enough state to enable you to copy your personal files off. If not, you'll need to use PhotoRec or a similar tool to do a file-level recovery.