My Book Essential 1TB -Fail to read -or- Recognize

Where to start? … 
My WD My Essential - External Hard drive  1TB has been acting up in the recent Month or so.

It takes 15-20 minutes for my computer to read.
When it’s finally accessible, and I click ‘My Book’ It occasionally freezes and reads (Not Responding) - This happening more and more frequently.
When I close the window it disappears completely, taking out my bottom Bar with it.
Occasionally in the Hard Drives folders say’s that it is empty. - Although it still says it has 200GB+ of data in it.
It freezes constantly, even when just trying to access a folder.

As for the Hard drive itself. - When turned on, The Fan (or something) inside Jerks around.
When turned on, the LED flashes repeatedly, stops, flashes again, stops and continuously does this throughout the time it’s on.

I think It must be having a hard time reading the files.
Any help? Ideas to fix this? 

Run chkdsk or any other software that can test and repair the partition

backup all data ASAP

-I attempted to run CHKDSK but when I click “start” to ‘Automatically fix file and system errors’ nothing happens.

The window closes and stays idle.
-My computer doesn’t seem to be reading the device itself anymore.

  • The Hard drive LED is stagnant. - No flashes, no blinking. Nothing. 
    -It very rarely comes up in the ‘My Computer’ Windows.
    -When it does appear, and I try to open it, the window reads Not Responding 
    goes a foggy white and closes.
  • And when I do manage to avoid this, and open the Device, it reads No files in this folder, 
    or something similar. - Even though it still says 700GB remaining out of 900GB.

Could it be the cord?
Or the device itself? 

Sounds like a drive problem

try another software to test and replace if no go