The CD has both the Windows and Mac programs on it. Are you doing 2018 now on your Mac? You need the file ending in .tax2017 from the Windows computer to transfer into 2018.
Just copy the .tax files on Windows to a flash drive to move to the Mac. They should be in your Documents then in the Turbo Tax folder.
If you are moving to a Mac from Windows or to Windows from Mac you will need to install the right program. If you have the CD it has both windows and Mac programs on it. If you downloaded the program you might need to call in and ask for the other download. Unless you have both downloads in your account already.
To Transfer 2017 from windows See Transferring from Windows
https://ttlc.intuit.com/community/tax-data-file/help/how-do-i-transfer-last-year-s-return-into-the-t...
