Quick note Nutdriver
32bit operating systems wont see more than 3gb of system memory, be it RAM (System memory) or VRAM (video memory).

EDIT..Should be 4gb Memory max, 3gb to user using the 3gb switch ( LARGEADDRESSAWARE) and 1gb for kernel memory...details below

I once used 32bit O.S with 4gb ram and 2 x8800gtx (768mb vram each, incase your not familiar with them). A whole lot of memory was wasted. And I think Nuts has an inclination of that. Read on:

Memory Limits for Windows Releases (Windows)

The reduction in available system memory depends on the devices that are installed in the computer. However, to avoid potential driver compatibility issues, the 32-bit versions of Windows Vista limit the total available memory to 3.12 GB. If a computer has many installed devices, the available memory may be reduced to 3 GB or less. However, the maximum memory available in 32-bit versions of Windows Vista is typically 3.12 GB.

The /3GB switch can cause some applications to have problems that are related to address dependencies or to a reduction in kernel space.

Bottom line: if you have 4GB of RAM in your system (or more), and you want to take full advantage of it, start using a 64-bit OS.

The following is taken from

http://www.dansdata.com/askdan00015.htm

For many years, it's been normal for personal computers to include a Memory Management Unit (MMU). MMUs were expensive add-ons for old computers, but modern CPUs all have one built in. A primary function of an MMU is to allow a computer to have "virtual memory", which in the PC world means "swapping" or "paging" data in and out of however much actual RAM you have as needed, keeping the swapped-out data in a file, or files, on hard drives.
Virtual memory is what allows your PC to have more than 4Gb of total memory, including the swap file(s). Memory management lets the computer augment its physical RAM, and lets programs running on that computer feel as if they've each got a simple solid space of memory available to them without treading on each others' toes. But virtual memory doesn't increase the amount of physical RAM you can have.
The explanation for the three-to-four-gigabyte problems is that modern computers include an arrangement conceptually similar to the old Upper Memory Area one. Many of the original Upper Memory Area MMIO reserved areas still exist today (for backward-compatibility reasons - otherwise you couldn't install DOS on a new PC), and a few more little ones sprouted above 1Mb as PCs went through their growing pains. Those are preserved today as well.
For this reason, a modern "3Gb" computer, which has 3,145,728 kilobytes of physical memory, is only likely to show something like 3,145,192 kilobytes available (look at the Performance tab in the Windows Task Manager, for instance). MMIO ranges "shadow" some of the physical memory, and so the system can't even see that RAM, at the hardware level.
3,145,728 minus 3,145,192 is only a shortfall of 536 kilobytes, though. So this 3Gb computer gives you 99.983% of the memory you paid for. Install more expansion cards in the computer, each of which is likely to eat some MMIO space for itself, and you'll lose a bit more memory. But you'll have to try pretty hard to lose even one whole megabyte.
I, for one, am OK with that.
But things get worse above 3Gb.
Large areas of the memory between three and four gigabytes are cordoned off for system devices in exactly the same way that chunks of the Upper Memory Area were purloined in the old days. Once again, the processor (and other system components) can talk with some devices by reading and writing memory addresses up above 3Gb.

Let me know if you want more...ive experienced it by the way, not read it, hence the reason I now run a 64bit operating system. In Nutdrivers case, the minute he installs a gpu with more VRAM he will be sacrificing more memory. He can throw the 3gb switch. However...

The /3GB switch changes the way the 4GB virtual address space is split up. Instead of splitting it as 2GB of user mode virtual address space and 2GB of kernel mode virtual address space, the split is 3GB of user mode virtual address space and 1GB of kernel mode virtual address space.
That's all.
And yet people think it does more than that.
I think the problem is that people think that "virtual address space" means something other than just "virtual address space".
The term "address space" refers to how a numerical value (known as an "address") is interpreted when it is used to access some type of resource. There is a physical address space; each address in the physical address space refers to a byte in a memory chip somewhere. (Note for pedants: Yes, it's actually spread out over several memory chips, but that's not important here.) There is an I/O address space; each address in the I/O address space allows the CPU to communicate with a hardware device.

In the end, the max he can use will stay at 4gb no matter what. Different devices will each claim/reserve a portion of that memory. So installing a GPU with more Video Memory will reduce total available memory even more.

Hope that clarifies the reality of having greater than 4gb memory (be it VRAM or RAM) on a 32bit operating system.

Note to nutdriver, you will still have more graphics rendering power and your son will be over the moon no doubt, I was only stating the obvious

Kind Regards
Taz