I was thinking about some interesting possibilities.
As with a 64 bit CPU you can do the same in 32 bit mode as in 64 bit mode, I can install XP32 (not XP64) in a 64 bit computer.
 XP32 have no idea of what is a 64 bit CPU and any memory above 4GB would be ignored, so I can make my own memory manager for accesing the memory above 4GB leaving the lower 4GB for Windows and normal memory access. My program will be able to use and abuse of the upper memory and Windows XP will have no idea that I am using this memory, so it will not disturb my memory and my memory will be under my own control.

Stupidity also evolves!