External HDD showing full but it is impossible

I have a WD 'My Passport' 2TB 2.5" drive which I purchased in September 2014. It has remained connected to my PC via a USB 3.0 port ever since and has behaved faultlessly ...until yesterday morning. Since then, the WD Lock device works as normal but as soon as it claims the drive has been unlocked, it appears in Explorer as F: Local Drive whereas it always showed as F: My Passport previously.

If I try to read the files on it Windows Explorer crashes, as does every other program I have open. If I try to open task manager, it won't and the only way to recover is to reboot using Ctrl/Alt/Del.

I tried the drive on a second laptop and it did the same thing however, this other laptop has MiniTool Partition Wizard installed so I used that to check the disk and perform a defrag. The chkdsk option claimed the disk was 100% full whereas prior to this happening it wasn't even half full. It also stated that a repair was impossible because 0 bytes were available for the log (or something like that). The attempt to defrag merely crashed the PC.

This drive has some extremely important data which I desperately need to recover so all assistance would be gratefully received.

Run Partition Recovery wizard (of Partition Wizard, get the latest free version if yours is not v9) for a quick scan. Post the screenshot here for experts to see. Also Disk Management - Post a Screen Capture Image

Include the exact model of the drive too.

If I run the partition recovery wizard, will it retain all my data or is there a risk of losing it all?
As far as the screen capture is concerned, Disk Manager just crashes when the drive is connected.

It won't do anything to data, scan, screenshot, quit out. :)

Right, well Partition Wizard doesn't want to launch. Mind you, it did the same yesterday but after about 20 minutes it finally opened. It's definitely this drive that's causing that.

Incidentally, I made a mistake, it's a 1 TB drive. Here's the info you requested:

WD My Passport 2.5" - 1 TB (931.48 GB).
Part #: WD88EP00 1088K-03

I'm unable to provide a screenshot from the other laptop as it doesn't have software for that purpose. However, Partition Wizard eventually completed its scan and, although I cannot access them, all my folders were displayed in its report. Disk Manager now shows the file system as RAW.

So I'm wondering whether I should get Partition Wizard to repair the MBR or follow its advice and download their Data Recovery Wizard?

No special software needed, press "Print Scr" (may be a Fn key combination), open mspaint and paste, then save as jpg.
Or try with How to Use the Snipping Tool in Vista

Post the wizard results, then double click the partition/s and take another screenshot. Post them all. So an expert can look and guide you.

Ok, thanks for the tip however, the screenshot only shows what I already said. As you can see, this is a French PC. Sain means healthy. I believe the reason why the drive cannot be accessed and shows as having 0 bytes free/used space available is due to it being converted to RAW. That likely happened following one of our frequent power cuts.

I will PM our data recovery expert, be patient and don't attempt anything if your data is important. :)

Launch PW.

Then on the left pane click on Partition Recovery Wizard > Next > Choose your WD external drive > Next > Full Disk > Next > Quick scan >Next.

After QuicK Scan completes you will get a Window showing the found partitions. Post the screenshot of it.

Double click on that partition/s also and show me the files.

You may then close the explorer,click on the Cancel tab to close the Window and then close PW. ( You may run Quick Scan again if needed.)

Wait for further instructions after I see the screenshot.