Hello,
the Windows license you have purchased will not work on Mac OS. Please contact our customer support
https://support.avast.com/Tickets/Submit that will gladly help you find a solution (refund, Mac business license, or something else you will agree with them).
We have two products for Mac OS:
- avast! Free Antivirus for Mac: The end-user solution available free of charge, the only thing that it is required is a user registration in 30 days from an installation. In one year from the registration you will be asked to register again for the next year.
- avast! Professional Antivirus for Mac: The same solution but with a business license. This product is currently sold only by our resellers, it cannot be obtained from our web site.
If you don't register a free product for one weak after the trial-period expiration, you will be autoregistered for some limited time not to be left unprotected. Nevertheless, if you followed the popup message on the Mac computer, you should never get to the point, where you would purchase a Windows license. Could you please explain to the support exactly the steps you were taking?
Best Regards,
Martin