Full Terabyte hard drive only shows 1 Megabyte partitioning



I deleted it using DiskPart tool in Win10 and it reformated using the same partition unallocated space. Maybe I don't know how to correctly stretch the unallocated space or something. I just want to get back to the default max size of the drive! Is there a recommended third-party software I might need to eliminate the partition (or extend it) which I can't do in Win10 itself?
 


There shouldn't be any stretch or extend needed.
Have you run the manufacturers diagnostic tool on this drive?
http://aps2.toshiba-tro.de/kb0/SPD7303VE0000R01.htm
 


I tried to run the diagnostic, but it wouldn't recognize the drive. It was a listed P/N matching the drive. I have tried and failed now with third-party, so I must assume that I now have a drive that only accepts 1 GB instead of its capacity of 1 TB. Ugh!!!
 


Did it ever work at 1TB?
 


My gamer stepson gave it to his mother for her schoolwork after he removed his softwares that nearly filled it while he used the whole TB.
 


So do we know the steps between 1TB of game software and the current "1GB"?
What happened?
 


All I know is that he off loaded (I think drag n drop) his files to clear space. He may have reformatted, but not sure. I think I'm giving up on this drive and heading to the store for a replacement. Thanks!
 


'Drag and drop' to a different drive defaults to Copy-Paste.
The original still lives on the original drive.

But that does not account for this showing 1GB instead of 1TB.