PAE would definitely enable them to use all 32GBs of physical memory. Both Windows and Linux have PAE support, but non-server editions of Windows still limit t

PAE would definitely enable them to use all 32GBs of physical memory. Both Windows and Linux have PAE support, but non-server editions of Windows still limit the physical address space to 4GB (although this might seem to make PAE support pointless, there are other advantages of PAE, like the NX/XD bit used for DEP). You are also correct that the per-process limit of 4GB of virtual memory is not affected by PAE. In case the advantages of PAE once again seem pointless, remember that a system can execute multiple 32-bit programs each with its own independent address space, so you can have, in theory, eight programs each using its own 4GB on a 32GB system without running out of memory. In practice, the platform imposes a limit of <4GB for physical memory, with the remainder used for legacy support and hardware DMA. Also, the operating system imposes a limit of <4GB for virtual memory, with the remainder used by the kernel.