32bit software on 64bit OS & Ram

Basically my question is this, I know that you can run 32bit programs on a 64bit OS. Can the 32bit program use more than 4Gigs of ram considering it's 32bit, or do I need the 64bit version to get over the 4Gig hump?

Most programs will be developed to use a specific amount of memory, thats why you will get minimum specs for software installs.

No, all 8 GBs of RAM will be addressed at all times with Vista 64 Superfecth. Unlike Windows XP Prefetch.

What is Superfetch?

What subsystem of Vista 64 allows 32 bit applications to run properly on the 64 bit OS?

The Operating system will have all RAM addressed at all times. As pointed out above, individual programs may have their own limitations, but that doesn't stop the OS from allocating (0~2GB) for one program, then allocating a different area (say, 2~4GB) for another. So no, it's not a waste.

http://msdn.microsoft.com/en-us/li [...] S.85).aspx

The OS itself isn't resctricting anything when talking about 32-bit. Getting around the 32-bit 4GB limit is possible... but not practical on consumer OSes... which is why you only see it in server environments. PAE caused more problems than it fixed... and you needed special drivers to take advantage of it anyway. It's much easier to move to 64-bit and leave the limit behind.

There are also restrictions in the Vista 64-bit versions. For instance 64-bit Home Basic has a 8GB RAM restriction while Ultimate has a 128GB restriction. There is no reason for Home Basic not to support more than 8GB other than money. Basic is cheaper so your restricted to use less memory than more costly versions. Fair enough.

Now the thing with the 32-bit versions is not only are we restricted to 4GB of RAM but the physical addressing is also limited to 4GB which means we cannot see the memory that is remapped above 4GB to make way for graphics memory, PCI etc. This means we cannot fully utilize our 4GB of RAM.

PAE is not the culprit here, AFAIK it was a number of badly written drivers which only seemed to come to notice sometime around XP SP1. Having tried the kernel mod test with 32-bit versions of Vista SP1, SP2 and Win 7 RC to enable more than 4GB of physical addressing while keeping the 4GB RAM limit in place I was able to utilize all 4GB of RAM. Other than the kernel mod, the system was the same as normal, no other modifications were made. At no time did I encounter any driver problems.

Yep, if we have no issues running 64-bit it's IMHO gotta be the way to go but we wont be leaving all the limits behind, just making them bigger.

I think the point is that 4GB is not the limit because the OS is named "32-bit", but because the kernel is restricted to 4GB. There isn't really any difference in hardware-addressing this amount of physical memory between the two OSes.