Hey there guys I need some advice and short but simple explanation on transferring iTunes backups from a windows PC to a mac. My gf has this old clunker of a laptop (windows) that just isn't worth salvaging and she is considering to switch over to mac OS. My only fear is she has synced and backed up the phone on the windows iTunes version, will the iPhone need to be reformatted if its plugged into mac version? I may have her get a newer windows computer instead if that is the case since somehow the HD storage of this laptop is apparently full and she can't literally put anything else on the computer. No backs ups, upload a photo etc; I may just have her use an external hard drive to open some space and delete the files so she can do a back up. If we turn on iCloud for her phone will it back up all the major essentials?