Look, a 32bit system is limited to 2^32 addressable memory. Subtract proc cache, video memory, and any other memory the bios addresses, and your 4GB of memory shows up as 4GB - the total hardware memory. Since this system has 3 video cards with 1GB memory each, it would be completly pointless to put more than 2GB in the thing. Do the math, and odds are pretty good that the system doesn't address the 2GB. Forget what the control panel says, Vista lists the installed memory, not the addressed memory. For that, look at the performace tab of the task manager.