I recently purchased 2x HP DL360 with dual Quad core and 4GB of ram. For some reason it only shows 3.24 GB
After some google, i found that it's the limitation on 32-bit processor. By adding the /PAE to the C:\boot.ini (hidden) solve the problem.
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows Server 2003, Standard" /noexecute=optout /fastdetect /PAE