I see no one else responded so I'll give you some tips. I just want to preface it with the fact that a huge drive like that scares me because I worry about time, heat and stress doing things that are hard on even a smaller drive.
First, if this is an external drive using a special controller chip to make it visible to 32bit Windows then that increases the stress, heat and time it takes to do a recovery.
My preferred option would be to hook the drive up to a Windows 7 64-bit machine and proceed to run Recuva to recover any deleted files.
since it will let you scan a specific location and make it much shorter and less stressful than scanning the whole partition.
If you are comfortable with Puppy then you can boot to it and install the TestDisk package which includes PhotoRec. Just search the Puppy forums for the TestDisk PET file
For Linux I prefer booting from Parted Magic because it already has the program PhotoRec on it.
These instructions are for Parted Magic
Mount the drive partition that you are going to recover the file to (must be different from the drive you are recovering from or you could overwrite data that you want to recover)
The mount/unmount selection button is second from the left on the bottom of the desktop.
Now in Menu->System Tools you should see PhotoRec
When you run Photorec choose
Select the disk
choose FILEOPT on the bottom of the screen
Press s to disable all file types
scroll down to .wtv and press spacebar to select it
Press enter and choose SEARCH to get back to the partition selection screen
Select the partition
Choose a directory on the disk partition you mounted where it will write recovered files (it will make a folder called recup_dir.1 there and put recovered files in it) and press C to start the search.
Your mounted disks are found in the /media folder. On my recovery machine I usually recover to my C drive which, once I mount it, is in /media/sda1
If it finds it, it will put it in the recup_dir.1 folder in the location that you selected.
Be careful that it does not overheat. Like I said, that is a huge partition. I get a little nervous around 500GB for recovery jobs and yours is 6 times as large as that.