>Not sure what "/NoExecute=OptOut" is on the end...
It means you already had PAE enabled ... (the option controls whether DEP - Data Execution Protection - is running, and in what mode; and if DEP is running then PAE is also running).
Note that on Windows 2003 SP1 PAE is always enabled, and it is actually quite hard to switch it off.
Further note that PAE does not make any more physical memory available to you than is installed in your server (and that is somewhat artificially limited to a maximum of 4Gb on Windows Server 2003 Standard), so you'll still see only approx 3.25GB of memory. But why?
It is a a limit of 32-bit addressing and the PC architecture. 32-bit adressing means we have a theoretical maximum range of 4GB, and the architecture means that that range consists of mixture of physical RAM and any I/O space required by devices. I/O space is mapped into the memory address range in a top down fashion starting at the 4Gb point and working towards 0 .... Until people started actually installing 4Gb of RAM this was never visible, but nowadays we get a conflict between the address for phycial memory and for I/O space, and in that conflict the I/O space always wins. So the [tt]physical memory[/tt] that you see reported available by the OS when you have 4Gb installed is actually [tt]installed physical memory - I/O space[/tt]. Examples of devices that consume I/O space are:
System BIOS
PCI Express configuration space and memory for PCI Express device(s)
Memory mappy I/O
Motherboard Resources (I/OxAPIC)
Chipset
PCI Enumeration
