Originally Posted by Dauntae
Also it's not just the system, If it's a old system with win XP 32 bit it will only see 3.5 gigs of ram, To see more you will need a 64 bit operating system.
Windows XP 32Bit can see and use 4GB of RAM, just the system properties doesn't display this.
Also X86 versions of Windows with the correct compatibility can enable PAE to allow 128GB of RAM to be installed, just anything above the 4GB mark on XP 32Bit can only be used by device drivers and not applications.
As for the original poster
They may have produced a few different motherboards for that model, so I would say open it up and get the motherboard number, then google it for the tech specs, this will give you the limits.