Yes, the *.taxYYYY data file can be opened in either the MAC or Windows version. You will need the software for that particular tax year if you want to OPEN the data file.
Or are you asking if you can transfer a prior year *.taxYYYY data file prepared in Mac, such as a 2017 return into a 2018 return in the Windows version? The answer is "yes" to that, too.
