badge :
Whwn moving from a 32 bit OS to a 64, a fresh format and installation of the OS is the only path.
there is no upgrade installation path available when you upgrade from a 32-bit operating system to a 64-bit operating system.
http://support.microsoft.com/kb/932795
Correct, but he's going from 64 to 32-bit and so using Easy Windows Transfer is not as cut-and-dry as it is when going from 32-bit to 64-bit. Due to the architecture change from 64-to-32 bit, migrating your app settings is not possible. Your files (pictures, docs, music) will transfer but not your settings, so you have to remember what they are.
But still, it's not impossible yet as you stated, either way requires a fresh format and install.
I guess my question to the OP is why would you want to go back to 32-bit?