If you are using a Tactrix or J2534 cable, you must install the drivers for your specific cable before opening the ETACS Decoder software.
If the idea of downloading sketchy ETACS software makes you uncomfortable, there is a modern alternative: with Mitsubishi enhanced add-ons or Car Scanner ELM OBD2 (App Store/Google Play). These mobile apps can modify some ETACS settings (though not all) without requiring a PC software download. mitsubishi etacs software download