100% Disk Usage External HDD

[Playcircus]

So, suddenly my WD External HDD 1021 is running at 100% usage, which is bogging down my entire PC while plugged in. There are multiple applications being cycled through when viewing the processes menu. These include System, Superfetch, Windows Defender, and a few other Microsoft apps. These only run at .1 MB/ps. Not enough to cause 100% usage.

I ran Windows in safe boot mode and the issue remained. The problem doesn't appear to be services. I also plugged the external into my laptop and the issue occurred exactly the same.

I am unable to run defrag, wipe the free space, run an anti-virus, and the drivers appear up to date. Any action performed while the external is plugged in causes the entire computer to hang-up. It even caused some startup issues that required a system restore in safe mode.

I'm wondering if someone could put me on the right track to possibly resolving this issue without formatting the drive or tossing it in the trash with 4TB of quality data stored on it. Does this sound like hardware failure, or more like a virus? I've done some research and my issue seems uncommon compared to others with the 100% disk usage error.

Any help is greatly, greatly appreciated. Thanks.

*Forgot to add that my laptop is running Windows 7, and is pretty much running stock. It has one game, Firefox, and drivers for my wifi. That's it. I only use it if my primary PC has problems.

[BC_Programmer]

If you start Resource Monitor you can see what processes are accessing that disk. (If you sort Disk activity by "File" all the requests for that drive should sort in the same location). I'd verify that the drive is not being indexed (Indexing Options in control panel).

I'd also suggest running chkdsk /R on the drive.

[Playcircus]

chkdsk appears to just stall. It won't run until I unplug the HDD.

Attached is what the resources monitor shows. The processes are all located on the C drive. They shuffle around quite a bit.

[attachment deleted by admin to conserve space]

[Playcircus]

Her is the list of files running.

It looks like sppsvc might be the culprit? Maybe Windows security is detecting malware on the external which is causing an error? Windows defender runs too. These are the only processes that are running besides the windows system processes.

[attachment deleted by admin to conserve space]

[BC_Programmer]

If chkdsk is hanging it is almost certain that the drive is failing or has failed. That very likely may be the cause of the issue- particularly since the usage amounts listed in Resource Monitor are trivial. My understanding of the Disk Activity % is that it measures the portion of time over the last few seconds (I'm not sure the precise time frame) that the drive has had an active request- that is, the system goes "I'd like to read data at this location, please" and then waits for the drive to respond with the results.  Failing drives often take a very long time to respond (due to attempts to correct for errors) or sometimes don't respond entirely, resulting in the Activity % for the drive sticking at 100%.

You'll want to try to get any valuable data off the drive that you can as soon as possible.

[Playcircus]

Alright, appreciate the heads-up!