I have two 4TB MyBook drives, one bought last week (now half-full) and the other bought last night (still empty, bought to duplicate the first one). These are my first 4TB WDs, although I have numerous 3TB, 2TB, and smaller WD drives and thought I knew most of their good and bad points.
My computers only recognize the first 4TB drive I plug into the USB port. I’m using Windows 7, fast computers, direct-connection (no hubs), both drives are plugged directly into AC outlet (no ext cords or spike bars).
I’ve switched cables, switched order of connecting, switched computers, even switched external drives (took one back last night because it was having this problem). No matter what, the same thing happens: both drives light up inside, computer sound acknowledges connection of both, but only one drive is recognized–the first one connected. If I disconnect USB on that first one, the computer doesn’t recognize the second drive unless both are unplugged from USB and then the former #2 is reconnected first. But if I disconnect the first one and then reconnect it, the computer recognizes it again.
Info, help, speculation, wild guesses all are welcome.