My WD Ext HDD is not recognised

Hey there,  this may seem like a stupid question, but i hope somebody can help me out. I have a WD external drive which windows wont recognise. I can see it while im in Device Manager, but i can’t get windows to open it. The led light is flashing slowly and it has not been dropped or bumped. I actually have two WD Drives that are doing the same thing. I also have tried them on various computers.

Please help!!!

Hello and welcome, 

Have you tried connecting each hard drive individually? Also see if the following links help

How to initialize or write a signature to a secondary hard drive or Solid State drive in Windows (8, 7, Vista, XP) 

WD external drive is not assigned a drive letter by Windows or Mac OSX and data on the drive is inaccessible 

If the problem continues you can try running a test with DLG. 

How to test a drive for problems using Data Lifeguard Diagnostics for Windows