Run ACTIAPnPInstaller.exe from your software source (often found in the Diagbox installation directory).

The device is typically recognized in the Windows Device Manager as an " ACTIA USB Device - USB Com Board Driver Driver Evolution

You install the correct driver, but Windows Update overwrites it with a generic FTDI driver. Solution:

If you are just looking for the raw INF files to force a manual install (advanced users only), they are typically located inside the Drivers folder within the Diagbox installation directory.