Mybook 3tb 2nd don't show

WD External Drives External Drives for PC
1

i connected mybook 3tb 1140 2 device

1st show

2nd don’t show

i go to computer management 

2nd device offline

how connect mybook 3tb 1140 2 device same time??

2

It’s a Windows thing check this post for a fix http://community.wdc.com/t5/Other-Externals/Problems-with-having-more-than-one-USB-2-0-WD-2-TB-Elements/td-p/285724

Joe