There are two distinct flavors of Windows 8. The first is for use on PC based systems and includes Windows 8, Window 8 Pro, and Windows 8 Enterprise. The second flavor is Windows 8 RT, which is for use on tablets.
Atrex 20, 21
Atrex 20 and 21 will currently run on Windows 8, but there are some known minor issues with components and images not displaying correctly. Please note that compatibility with Windows 8 may be discontinued without notice.
Atrex 16, 17, 18, 19
Atrex 16 newer are fully compatible with Windows 8 PC as a standard application. Atrex is NOT compatible with Windows 8 RT.
Atrex 13, 14, 15
Atrex 13, 14, and 15 appear to be incompatible with Windows Windows 8 PC as a standard application. Recent security updates have caused random errors with Atrex and in some cases the inability to start the application. Atrex is NOT compatible with Windows 8 RT.
Atrex 12 and Older
Older versions of Atrex, 12 and earlier, are incompatible with all versions of Windows 8 and are NOT supported on that platform even when run in compatibility mode.