Windows 7: Missing Hard Drive Space

I researched some other posts that sounded along the same lines and i have tried several things but i still can not seem to find the missing space.

I have a 1TB WD Black formatted to 931GB. I realize this is not going to be exactly 1GB.

Under My Computer, i have 84.1 GB free of 931.

When i use WindDirStat as recommended by other posts, it tells me at the top how many GB are on this drive. It says 675.6GB. I am wondering how i am missing (931-675.6-84.1 =) 171.3GB!

I have checked the "My Computer --> Properties --> System Protection --> Configure for this drive and it the current ussage is set to 0 bytes and max usage set all the way to the left with the "Turn off system protection" box enabled.

I've set to show hidden files and can find none.

Any ideas about the missing 171.3 GB? It's enough to feel a little frustrating.

Regards

What exactly does it show in my computer and in disk management?

...and yes I know I letter my drives in a way that makes sense to no one but me.

Have you run Disk Cleanup as there are several things that can eat up disk space such as Windows.old, Hibernation, Shadow Copies, Temporary Files etc. etc.?

under "My Computer" it says 84.1 GB free of 931

under "Disk management" it sais Basic, NTFS, Healty (Primary Partition), 931.51 GB, Free space 84.15GB, 9% free, Fault Tolerance No, Overhead 0%.

This is just a media storage drive. Not a boot drive.

under "Disk management" it sais i can use Disk Cleanup to free up 0 bytes of disc space on this drive (I selected the correct drive when opening up disk management).

I have tried emptying the recycle bin (it is empty, but no effect)

I've tried cleaning up system restore and shadow copies (no effect, system restore turned off)

Hybernation/sleep are disabled in the registry

I did not try the "remove programs you do not use" as this button makes me nervous, but i know that i have no programs installed on this drive.

Have a look in your temporary and appdata folders.

there are no temp or appdata folders on that drive. I even tried to search for them just in case and no results.

OverDisk - Download

Give that a try

Does that program do anything that WinDirStat does not? Trying to keep the list of programs to a minimum

Well something is misreporting I think.
If disk management shows no mystery partitions or anything out of the ordinary and the drive is formatted properly which it appears to be I can see no reason to believe anything is wrong here.

The only way to be absolutely certain would be to reformat the drive at this point since nothing seems able to actually tell you where any mystery space is being used.