If libCECTray fails to open, shows an error on startup, or stops working after being added to Windows startup, the cause is almost always that only cec-tray.exe was copied — without the supporting DLL files and the NetFX folder it depends on.

Symptoms

• Double-clicking cec-tray.exe does nothing — no window opens, nothing appears in the system tray
• An error appears referencing a missing .dll file
• libCECTray worked when launched from the installation folder but stopped working after being moved or added to Windows startup
• The adapter appears to be functioning (detected in Device Manager) but the tray application will not start

Cause

cec-tray.exe is not a standalone executable. It depends on a set of DLL files and the NetFX folder located in the same directory as the executable within the libCEC installation. When only the .exe is copied elsewhere — such as to the Windows startup folder or a different location on the drive — the application cannot find its dependencies and fails silently or shows an error.

Fix

Option 1 — Run from the installation folder (simplest)

Do not copy or move cec-tray.exe. Run it directly from the libCEC installation folder, which is typically:

C:\Program Files\Pulse-Eight\USB-CEC Adapter\netfx\

Option 2 — Add to Windows startup correctly

If you want libCECTray to start automatically with Windows, do not copy just the .exe to the startup folder. Instead:

1. Press Win + R, type shell:startup and press Enter — this opens the Windows startup folder.
2. Right-click inside the folder and select New → Shortcut.
3. Browse to cec-tray.exe in the libCEC installation folder and create a shortcut to it.
4. Place the shortcut in the startup folder — not a copy of the executable.

A shortcut launches the application from its original location where all its dependencies are present.

Option 3 — If you must copy the files

If you need the files in a specific location, you must copy the entire contents of the libCEC installation folder — including all DLL files and the NetFX subfolder — not just cec-tray.exe alone.

Verifying the Fix

After making the correction, launch libCECTray and confirm:

• The application opens and the Pulse-Eight icon appears in the system tray
• The status bar at the bottom shows "Opening connection" followed by a green indicator
• If you added a startup shortcut, restart Windows and confirm the tray icon appears automatically

Related Articles

• Getting Started with the USB-CEC Adapter
• CEC Adapter — Windows Setup