Why can i not see partitions over 1.5gb while in windows/bootcamp?

I have a mid 2011 imac 21.5 and while I am in windows that was installed with the bootcamp assistant, it won't let me see one of my external drives that is 2tb.

I can see the other partition on my main drive which is my main os x partition just fine. And another usb that is 1tb can also be viewed with no problems.

When i am in os x I can see the 2tb drive just like any other so I am at a bit of a loss.