Western Digital not recognized in windows after bootcamp

Hello, i just bought a new imac, and after installing windows 7 with boot camp i have a problem with 2 WD My Book Essential 3.0 external hard drives that are not being recognize when i boot in windows. In order to make them work i have to unplug and plug them again. Then, they will work fine, but its kind of annoying to do that.

The external hard drives format is ntfs.

Any way i can fix this problem.

Tx a lot in advance.