hard drive space has gone missing, have tried all solutions

Good day ladies and gentlemen!

As you can probably assess from the thread title, There is a really weird problem afflicting my computers hard drive. The Hard drive with the problem is an advertised 750 GB Western Digital hard drive, with 684 available gigabytes.

The problem I am having is that a mysteriously large amount of hard drive disk space has disappeared from being available, and has left me to have only about 100 Gigabytes left (originally it had whittled down to about 100 MB before I deleted a large amount of miscellaneous files), from my estimated 500 Gigabyte's I had available to me last week, but there is still a lot of hard drive disk space un-accounted for. I've been perusing the windows 7 forum and have tried different solutions to no avail. The methods i've tried are as follows:

-Updating my BIOS, USB, Hard drive and other miscellaneous drivers
-Using Disk Cleanup
-Using Disk Defragmenter
-Using WizTree, WinDirStat, and TreeSize (free) to find out what was eating my HDD Space
-Phisically taking the Hard drive out and checking out what's wrong with another computer
-Deleting many large files not necessary to function

With the help of WizTree and the other programs, i've noticed that they only can account for one fifth of my hard drive, leaving the rest to the unknown.

I've attached screenshots that may help with diagnosing my problem.

The images should be self explanatory, and I hope they can help in alleviating this issue.
I feel like i've exhausted my options shy of actually taking the rig to a computer specialist. Do you think you guys know what's going on with my hard drive?

Here's my systems specs:
Lenovo Y480
Windows 7 Home Premium 64 Bit
Intel(R) Core(TM) i7-3610QM
8.00 GB
GeForcer GT 640M LE
WDC WD7500BPVT-24HXZT3 750 GB HDD

Thank you so much if you could provide any input!

-Wammeze

A screenshot from TreeSize would be VERY USEFUL to compare with WizTree.

Wiztree is very quick because it gets all its data from the MFT,
but is therefore not suitable for FAT32 format.
TreeSize is slower - I guess because it trawls through directory structures.

When I scan Partition R:\
Wiztree IMMEDIATELY shows
Total Space 742.2 GB
Space Used 736.4 GB
Space Free 5.8 GB
Then it spends less than 4 seconds scanning the MFT,
and a further 3 seconds preparing the "Tree View" which lists the folders, sizes, and numbers of files.
This is when I see a maximum total of 316,004 files in R:\

TreeSize Free takes 10 seconds building up totals,
During that time its total size for R:\ gradually creeps up to 735.9 GB.
It only sees 315,986 files

TreeSize is unable to see the folder R:\$Extend\ or the 8 files which WizTree reports
WizTree also sees and reports these 9 files, which TreeSize also ignores
the 436.8 MB file R:\$MFT
and 8 more R:\$etc files that total 100 MB

My guess is that WizTRee and WinDirStat are telling you the same thing because they both use the MFT.

If Windows Explorer properties and TreeSize agree that C:\ has about 576,000 files your problem might just be an error in the MFT entry that states the Free Space.
If Windows Explorer properties and TreeSize indicate a vastly different quantity of files then the MFT could be horribly corrupt.

IT IS POSSIBLE THE MFT IS CORRUPT,
Otherwise there would not be a backup/repair mechanism which I believe involves $MFT and MFTMirr,
and hopefully there are experts here who know the relevant procedures and magic spells.

I am not sure of the prudence of :-
attempting to detect and remove malware files if you are accessing it via a corrupt MFT;
or of attempting to investigate and maybe repair the MFT in the presence of a RootKit
That is a question to ask at any malware fighting forum.

@ICit2lol
Sorry, I do not see any reason to suspect malware, but perhaps you have seen this sort of problem before.

I would have thought the "Healthy OEM" partition to be common when a P.C. is supplied with Windows pre-installed,
and having a separate partition for a Pagefile is fairly common
(though it is a beginner's mistake to have it on the same Drive as C:\)
I am surprised that C:\ is marked as Active instead of the 200 MB partition at the start of the Disk.

Regards
Alan

Hey guys, thanks for the wonderful input!
I for one feel like I know what I did to cause the hard drive to be this way. The problem began when chkdsk started randomly and when I turned on the computer, I stupidly shut the computer off midway through the process twice because it was taking far too long and I needed to get things done on a schedule.

Now that I've ran chkdsk, it's been running for at least 8 hours and I'm not too sure how much longer it's going to take, as it is on the "adding bad clusters to the bad clusters file"

Specifically it says that it is" adding 147346318 bad clusters to the bad clusters file. " is that an excessively high number for the computer to be reading? Does it mean something, and how much longer do you think it will run for?

Thank you guys once again so much for all of. Your input!

-wammeze

Is it seriously that bad? I mean chkdsk finally finished, and now the memory available is down to 750 mb :'( I don't have the means to backup everything, as I am out of country and my extra backup hard drive is in another town is my hard drive slowly dying?

Hey whs

I am based out of Canada and am currently visiting relatives in Texas. They do sell hard drives here, and I do have a one year subscription with the best buy geek squad, it's just I want to try as many things as possible on my end before I have to spend some money.

This is not the first time something has happened to this brand of hard drive that has given me issues, so i'm understandably starting to lose faith in WD.

Do you think that if I back up only the most important files onto an external drive, completely wipe the original hard drive, then put it all back onto the freshly formatted hard drive, will it alleviate this deterioration problem?

Thanks for the help, I really appreciate it!

-wammeze

PS-Attached is the tree size image you requested.