My Book 3.0 1TB is not recognized by win 7 64bit

I got a motherboard ASUS P7P55D-E (USB3). Operating system is win 7 64bit.  The Book is not recognized.

Also connecting the Book to a USB2 socket brings no recognition.

Sticks and another external HD (USB2) plugged in USB3-socket are recognized. The Book is recognized in an other PC with win7 32bit with a gigabyte motherboard.

Looks like a special problem between ASUS-Board and My Book.

Please help. Thanks.:cry:

Have you got the latest updates for drivers and board?

Joe