Accidentally Deleted External HDD using DiskPart

THANK YOU VERY MUCH GUYS!
I was able to fix it using TestDisk instead.
For people who want to know what I did:

Well of course the problem was that I deleted the file structure itself.

So I used TestDisk to restructure the HDD. I do not know if overwriting a new partition onto it will wipe everything, but in my case, fortunately, I didn't make a new partition yet.
I ran testdisk to restructure it and then used Disk Management to assign a new Letter to the drive that was restructured.

I knew the files were still there, just that the drive itself, the holder was deleted.

Finally can get back to work. Thank you again guys. :)

Good to know that you were able to successfully use TestDisk to find the deleted partition/File System. You must have definitely written the found partition structure/File System using TestDisk. Just one query: when coming to select the partition type which one did you choose [Intel] or [EFI GPT]? Did you [Analyse] or went to [Advanced] Filesystem Utils? More details on what exactly you did will be helpful.From your Disk Management screenshot I guessed that your 4TB drive must have been initialised as a GPT drive. Is that right?

Hi Jumanji,

Yes, I used EFI GPT since I had exFat on my previous one. I had to Analyse, then check if my files really were there. Then after that, I went and wrote the file structure. It really depends on your prior formatting. And testdisk actually helps you with that once you select the disk itself. goes to the default

As far as I know, there is no way one could defeat the internal hardware encryption of the Western Digital external drives. When questioned, Western Digital in their forums replied that the users have always the option to buy the non-encrypted drives - the Elements. But the problem is many users who buy the Western Digital My Book, My Passport etc. don't even know that the drives are encrypted till the internal electronics fails and they come in for Data Recovery. We have to throw up our hands and redirect them to WD Data Recovery Partners who will naturally demand their pound of flesh, knowing fully well that they are the only ones who can recover and decrypt the data.

If one had bought two WD external drives at the same time from the same vendor, these will most likely be from the same batch and one can replace the faulty internal electronics board with the other and retrieve the data. But here again Western Digital makes it difficult by integrating the SATA to USB bridge to the HDD. It will require professional help to replace the card.

Recent research indicates even those who wanted their data to be secure and willingly chose to buy the hardware encrypted drives which can additionally be password protected, are not as secure as they would have thought it to be. :)

Just some that appeared in Oct 2015:

Western Digital's hard drive encryption is useless. Totally useless
Western Digital's hard drive encryption is useless. Totally useless • The Register

Western Digital self-encrypting hard drives riddled with security flaws
Western Digital self-encrypting hard drives riddled with security flaws | Ars Technica

Western Digital encrypted external hard drives have flaws that can expose data
Western Digital encrypted external hard drives have flaws that can expose data | PCWorld

Western Digital’s encrypted hard drives come under fire from security experts
Western Digital?s encrypted hard drives come under fire from security experts | ExtremeTech