Try using Windows Server 2003 Enterprise or R2 Enterprise. im using it with 8GB and it utilizes full 8GB through PAE(Physical Address Extension)
Tested 2K3 32 bit back when I first built the rig, PAE allows the system to see it, but 5-10 minutes into video editing from 5GB ram drive it always gets the blue screen. Think issue was 32 bit application does not know how to handle the addressing of more than 3GB even with PAE. Thus making PAE only good if you need multiple programs using modest ram, not single program hogging all the RAM. This did/does not happen on x64.
Last game I played was 501 and I doubled out from 40 with a double 20. Won a few rounds. I bet you can't guess what game I was play. Tungsten and Pig Bristle cause I like true aerodynamics, none of that plastic/electronic crap for me. Urie, will check it out.