If you want to see the memory status on your Windows host with reserved memory and all use Microsoft's tools RAMMAP https://technet.microsoft.com/en-us/sysinternals/ff700229.aspx
2x 6GB + 4GB = a lot on a 16 GB host with it's own OS. There is probably some memory being swapped. Are you sure your W2K8 machines needs 6GB?
I bet your system would run smoother if they are scaled a bit down if that is possible.