Go to your account. Deauthorize the Windows version. Download, install, and authorize the Mac version.

Open a support ticket if you have problems, but I don't think you will.

You get two installs/authorizations of full Finale 2014.5. So you can add the Mac install without deleting the Windows authorization if you want to and have only (so far) authorized the program on one computer.

I am using Finale 26 for Windows. Is it still true that I can also install on my Mac? So many of the pros on YouTube (and in the community forums) use Mac that I think it might be easier for me to switch.

Yes. As long as you only have two authorized installations, the platform doesn’t matter.

Just a heads up: If you own an ARM Mac (M1, M2…), know that 26 needs to be run over Rosetta II. The first ARM Native version is the current build, 27.3. This is not an issue with Intel Macs.