In Brief, I accidently ran diskpart clean command from cmd on windows installation and lost all my partitions, then mounted the entire drive as one big partition and then installed windows in it. My important files were in the other partition that I previously had. I did not install anything else on my COMPUTER after the windows installation and did not store any data in it either in order to save the disk from being overwritten. please help me get my data back.

Now the full story...
So until now you already know most of the story, let me tell you the entre story now. My friend gave me his laptop to format it and REINSTALL windows, which should have been a very simple and straightforward task. He was having very important data in the documents folder (around 80GB). The drive had 3 partitions, one for windows (C) and other two for storage (D and E), so in order to take backup of data I copied all the data that was in the documents folder (which sits in the C partition) in to the D partition under the backup folder. So, I had two copies of the same data among which one was going to be deleted as it was in the documents folder which in turn is in the "C" partition, and the other copy was for the backup to get the data back after the successful installation.

After these preliminary steps for the format, I downloaded windows and made a bootable pen drive. I restarted the computer to load from that bootable drive that I created. After entering in to the setup and doing some initial tasks (like selecting the language and time zone), I entered the step in which I had to choose the drive (logical drive) in which I had to install windows (yes, I was doing an advanced install... I always do that). From there, I choose the "C" drive (which I knew from the partition size) and formatted it. when I choose that very partition for windows installation, it showed the error that said the drive was in the MBD format and needed to be converted into the GPT format. I never had seen this error before so I did some googling and found an Instructor whom I simply followed. The instructor ran "diskpart clean" command from the cmd (which we open using shift+f10) so I did the same. after refreshing the dialogue box where we had to select the logical drive to install windows into, I realized that the command had deleted all my partitions. So, after this command I had one big unpartitioned drive.

After this WHOLE thing I was in panic, and without thinking straight I mounted the entire drive as a single big partition and installed windows in it, thinking that I will recover all the lost data after the installation as I thought the installation will not overwrite the data that was in the D drive. After the successful windows installation, I installed two data recovery tools in my friends laptop and tried to recover my partitions and the data, both of them failed to do both. the two tools that I USED were "steller" and "easeus".

After those two installs, I did not install anything else on my friends computer and neither did I store any data in it in order to save the drive from being overwritten. I of course tried a bunch of other data recovery tools, which I installed on my USB pen drive, which offer a free scan, but got the same results. After this, I did ask some questions on Reddit and other places and found two other data recovery tools that were very powerful. They could deeply scan the drive sector by sector. Those tools were "getdataback" and "r-studio". I first tried getdataback but the file log stopped after first 5 percent which did not include the data I was looking for and I did not get any data log after the completion as well. So I tried other tool which was "R-studio" This tool also did the same thing (deeply scanned the drive sector by sector) and got the same results.

In the GUI of R-stuidio, I observed that that the few percentage recognized some sort of data, but after 5 percent all it could find was unrecognized sectors. From this I concluded that the sectors on the drive might be unrecognizable.

As the data recovery tools were able to get some data back from 2 years before (from the C drive, like some application logs), I think that the windows installation does not over write the entire drive but only overwrite the space that it needs. One thing that I don't know is weather the process of deleting all the partitions and creating one big partition overwrote the entire disk or somehow killed all the data traces. The data recovery tools seem to be recovering the data that was on the C partition before and not the data that was on the other two partition as if the other partitions were never there.

the questions that I have are:

1) How to get my data back?
2) What are those unrecognizable sectors on my hard drive?
3) Is my data still on the disk?
4) - (a) Why the data recovery tools can find the data from the C partition only and not from the other partitions?
    - (b) If I re-create the partitions that were there before, will then the data recovery tool be able to recover the data from the partitions that I had before?
5) If I cannot recover the data by myself, can the recovery firm like "steller" do it?

Please help me get my friends data back... It contains very important stuff.
Hi

diskpart clean command works at a drive level not on individual partitions so when you ran that command you erased all the data from the drive including the D partition. I'm surprised that there was any data to recover at all. Certainly if there was any data r-studio would have found it. Also windows 10 normally recommends GPT partition with an SSD drive which would only take seconds to be erased with diskpart clean.  I feel you have done all you can and have to face the fact the data is gone.


Thankyou so much for your response, John. The drive my friend's laptop has is a conventional hard disk (seagate sdc001 1TB). When I ran the "diskpart clean" command, it took a fraction of a second to complete. I know some tools that are used to completely wipe the hard disk making all the data un-retrievable by overwriting it, but those tools take like a day to finish the task. This create a hope for me that the data might still be there.

Also, as I was extra cautious after creating all this mess, I simulated the entire thing on a USB pen drive. I took a 32GB pen drive and first formatted it. Then I made two partitions of it (around 15GB each) and put video data in the first partition and some documents in the second partition. Then I used the "diskpart clean" command on my pen drive (just I did with my friends hard drive) and both the partition got lost. I then mounted the entire disk space of my pen drive as a single partition and put some data in it to overwrite some space of partition 1 (simulating windows install).

After this, I ran R-studio with deep scan on it. The R-studio recovered all the data that was in the second partition and also recovered some data from the first partition (because some I overwrote, as I was simulating windows install).

So my experiment showed that the data stored in the other partitions can still be retrieved after the "diskpart clean" command and re-installing windows. I might be wrong, and I invite you to correct me and advice me what I should do next.

I would also want to know if the recovery firm will be able to recover the lost data. My last option is to send the drive to the recovery firm, but as it is expensive I want to do anything that I possibly can before PROCEEDING this last option.Not from an SSD it wontrbeigh you are correct I tried diskpart clean  with a mechanical drive and used both R-studio and Active partition recovery. R-studio needed to scan the whole drive before displaying the lost partition. Perhaps you are not letting R_studio go right thru the drive or at least to the position of the 2 nd partition. Active partition recovery allows you to scan only the area of the disk where the partition is likely to start so puts less stress on the drive and therefore a lot quicker.

Before you attempt a recovery and a recovery company would do is diagnose the health of the drive you could use HDsentinel from here   https://www.hdsentinel.com/
If this shows the drive is failing send it to a recovery company. 
That being said my point is if it;s an SSD drive your data is waay gone...just sayin.