It was my understanding the 32bit OSs can not count high enough to access the memory above 3.2GB.
From Here
232 = 4,294,967,296 bytes 4,294,967,296 / (1,024 x 1,024) = 4,096 MB = 4GB
It's different for 64-bit:
264 = 18,446,744,073,709,551,616 18,446,744,073,709,551,616 / (1,024 x 1,024) =...