The other windows PC is still in use for things that I can only do on that platform (it gets turned on briefly a couple of times a week). One of those systems has been retired and replaced by the MacBook that I'm typing this on now.

My situation is that I have two lifetime keys, both initially used on Windows systems. The quote above seems to set equivalence between the versions for the different platforms, which changes the game entirely - it's now admitted to be the same product - just expanded in scope. In another thread a couple of weeks ago treed seemed to say that lifetime keys would not work with, or be issued for with the Mac version (the unstated underlying message being that they were different products) Please let me know if you have any additional questions.

If you have the old lifetime license, that license key will only work on Malwarebytes 3 for Windows. If you purchased your key before July 31, that license key will only work on Malwarebytes 3 for Windows. If you purchased your key after July 31 (when Malwarebytes for Mac launched), this 'new' license key can be used to activate Premium on either the Windows or Mac version of Malwarebytes. My apologies, I thought you meant the actual products running on their respective OSes.

Malwarebytes mac license key