Aaron,
Thanks for the reply that kind of makes a bit more sense. I see in 2008 it shows about 1GB cached but even still as you pointed out Windows shows that as being "used". One thing I'm still getting tripped up on is that even is you "subtract" the 1GB cache from the 4GB that still wouldn't equal the 12% that vCenter is showing.
Is there something else in the background or another explanation that would show the difference?