I am looking to upgrade Avast Anti Virus across my desktop, my MacBook, my brother's laptop and my mother's laptop (currently all are running the free version), and I am wondering if I were to buy 5 licences, if the licence file that is emailed will work on the MacBook as well, or if it runs a seperate kind of file for that? And yes, I know I have only mentioned 4 computers here and mentioned the 5 licence purchase (I can give the 5th to my father).