sorry, but you don't know what you are talking about on 32bit windows xp your application can never ever address more than 2^32 bytes of virtual memory without the use of special api functionality (awe api), because your logical addresses are still 32bit wide, so your pointer will always be 32bit wide - pae or not. however since those days when intel brought us the pentium pro, they added 4 bits to the physical (!) address, giving us 2^36 bytes of addressable physical memory (64GB). but besides the fact that even pae enabled xp is limited to 4GB of total physical memory, you have to keep in mind that the address translation process from 32bit virtual memory space to 36bit physical memory space is entirely handled by xp's memory management subsystem and therefore totally transparent to the user.... for more information on this topic you may review these sites: http://en.wikipedia.org/wiki/Physical_Address_Extension http://www.microsoft.com/whdc/system/platf...PAE/pae_os.mspx http://www.microsoft.com/whdc/system/platf...PAE/PAEdrv.mspx have fun
