amtay, a 64 bit Operating System can not be "converted" to a 32 bit operating system. As to why, it's because a 64 bit OS sends literally 64-bits of data in one clock cycle whereas a 32 bit OS sends literally 32 bits of data in one clock cycle. You'd have to rewrite the entire OS to send data in two clock cycles instead of one for it to work in 32bit and at that point (even if it's theoretically possible) performance would be cut in half as it would take twice as long to transfer the same data.
I'm always amazed when I see these threads.