Ah, I thought of searching for QT5 on my Mac and what do I find? instructions:
To run ATFViewer on Windows:
Perform the following steps as a one time setup on your machine:
1. Download QT SDK from https://download.qt.io/archive/qt/5.7/5.7.0/qt-opensource-windows-x86-msvc2015-5.7.0.exe.
2. Run the downloaded exe file & install to C:\QT.
3. Once the installation is complete, copy the following dll files located at C:\Qt\Qt5.7.0\5.7\msvc2015\bin
to the folder <AIR SDK>\atftools\.