3GB switch & windows occupied memory

[msprung]

Hi:

I have a question concerning the memory use of windows xp sp2 with the 3GB switch enabled. I have 4GB of RAM installed and am wordering why the largest continuous free memory block is only of the order of ~1.5GB and not around the ~2.7GB of free memory.

Does windows occupy the address space from 2-3GB instead of the natural position of 3-4GB? This question is related to the hotfix mentioned under KB894472.

Thanks

Michael