Open STB_Upgrade_Tool_v4.0.2.exe . You will see several configuration options:
This guide covers everything you need to know about using this specific version to flash firmware and recover your device. What is STB Upgrade Tool Ver 4.0.2? stb upgrade tool ver 4.0 2
The tool should now show a progress bar indicating "Initializing" followed by "Downloading." Open STB_Upgrade_Tool_v4
Most STBs use a 9-pin serial cable or a 3.5mm jack-to-RS232 cable. stb upgrade tool ver 4.0 2