HDD WD Casviar 2TB not recognised after partial run of deep defrag

I ran a deep defrag with NU16 and got into a couple of hours.  When I got back to the system it had an error message which referred to MBR.  Prior to running the software the computer was stable and no issues experienced...

I have since attempted all sorts, and with win 10 disk management can see the drive, and a drive letter, although will not let me initialise the drive.  I see the drive (SATA 2) in my old tower from where it came from when going through BIOS but when I select in boot sequence it just goes to the error message.

I have also used an enclosure to no avail - anybody got any suggestions, I feel that it was the running of the software and not a hardware issue.    You can hear the disk spinning etc....

Really frustrated, as the drive had no previous issues, so wonder where I can go from here to access the data again.

Any help will be greatly received.  Thank you.

Pb

I have also used an enclosure to no avail

Just to clarify before going on with some suggestions:

I take it by that that you mean you pulled the hard drive out of the desktop(?) PC case and put it into an enclosure connected to something by USB? If so and what you tried without success was to boot to it you cannot (normally at present) boot from a drive connected by USB to an operational PC. Windows will let you look at the contents of the drive but not boot it up like if it was inside the case and part of the system.

You say that by two ways you can see the drive ... but can you see the contents of the drive -- the various files etc?

If you can fill on all that as well as this bit of my boilerplate

To get you the best advice, would you give us some more information about your system:

The version of Windows that is on it and that you are trying to boot to is Windows 10?

Please say which subversion: Home or Pro and whether it is 32 bit or 64bit (If you don't know but it's a commercial model PC please say the Make and Model Identification which would enable us to look it up.

the Name and Version ID of the Norton product that you are using -- Help or Support / About is where that is, in the format of nn.nn.nn.nnn where n is a number.

If you have the COMCAST version of Norton 360 / Security Suite and not the normal retail version please be sure to tell us.

Please also say what internet browser you are using -- name and version number ...

If you get any error messages please give the exact wording of them as well as any other background that could be helpful.

then I have some suggestions that may help you resolve the situation although perhaps not why it happened. But we can touch on that later.

Did you make a recovery disc/thumbdrive from this when it was operational?

I'll be offline shortly until early evening so don't be surprised if you don't get a quick next step from me.