Only 1 Drive is visible - the other 1 is Offline

Hello , i have 4 WD portable hard drives being connected to my PC USB. 1 pc of 500GB 1 pc of 250GB and 2 1TB. Both 500 and 250 GB are visible and it show they are online. The weird thing is that with the 2 1TB. Not both of them can be connected at the same time. If I do connect them both, only 1 shows and the other says offline. The 1 which is connected first will be the one that shows on my computer. I am using Windows 7 64bit and USB 2.0. Question, is there a trick that i can do here so that i can see both at the same time? I did formatted and changed some settings in the properties and still both cannot be connected at the same  time and can be seen. Any help is highly appreciated.

It’s a Windows issue this thread explains and has a fix