Hi. Your song will end up in a folder with the title. This will contain a bunch of folders like "media", "bounces", and a file with a [.song] extension. Just transfer this named folder containing the [.song] file and it's contents between your machines. ### Presonus uses the [.song] file which is proprietary to studio one. As long as you grab the right folders then there should not be an issue switching between Mac and Windows. You might get errors like missing external devices if you use hardware like the Atom on the originating system that aren't available on the machine you transfer to. You should also try to make sure sample rate and bit depth match between the two systems for optimal performance. I this with one CAVEAT - I only use windows systems and transfer between two windows systems.