My Windows 7 PC an't see My Passport 1TB External

My Windows 7 PC an’t see My Passport 1TB External.  It also can’t be seen by my MacBook Pro, my iMac or my Mac Air!  When I first plugged it into my MacBook Pro to offload some of the hard drive there, it told me it was not readable and after a few tries (and getting the same error msg), I clicked on ignore.  Now it isn’t even visible on any of my computers.  If only I could see it, I would reformat it, but I can’t even see it to do that! 

The drive is spinning and the power LED is illuminated (and I can feel it running).  I’ve tried two different connectors and both provide power to the drive to spin and illumnate the LED.

HELP!

Hello,

Check if the drive is seen in disk management on Windows or disk utility on Mac. If it is seen then you can format it from there.

How to partition and format a WD drive on Windows (8, 7, Vista, XP) and Mac OSX

If the drive is not seen in disk management or disk utility then its time to get it replaced.

How to get an RMA, (Return Merchandise Authorization) or replace a defective product under warranty