Trying to connect 2 external passport hard drives

I have 2 western digital external passport hard drives.  Same exact hard drive.

I am trying to double back up one to the other.  I connected both to my computer.

Both drives show up on the Open Drives/Properties Screen.  However, can only open one of the hard drives to access data.  The other one wont allow me to open. 

When I the one hard drive, the other one opens up. 

So, there doesn’t appear to be issues with hard drive working.

I have 2 laptops and 1 desktop - tried to do with all and same thing happens.

I tried naming the one hard drive Photos and the other Photos 2 but they still won’t both open at the same time.

Any ideas on how to get both of them to open at the same time.

Hi there and welcome to the WD community.

What operating system are you using on your computers? If you are using a windows based system id recommend following this link:

http://wdc.custhelp.com/app/answers/detail/a_id/6571