TaskbarMonitor

Hardware monitor that runs directly inside the Windows taskbar. Written in C++17 using Win32 APIs and double-buffered GDI. Uses under 10 MB of RAM.

The logo source is assets/logo.svg. The Windows icon and PNG are generated with python tools/generate_icon.py (requires Pillow and PyMuPDF for asset generation only).

Metrics

The monitor renders a two-row status block directly onto the taskbar.

Metric	Display	Data Source
Network	Upload / Download speed	GetIfTable2 across active non-loopback interfaces
CPU Usage	CPU %	GetSystemTimes kernel, idle, and user differentials
CPU Temp	Degrees Celsius	PDH thermal zones, WMI MSAcpi_ThermalZoneTemperature, or load-based estimate
GPU Usage	GPU %	PDH \GPU Engine(*)\Utilization Percentage (capped at 100%)
GPU Temp	Degrees Celsius	NVIDIA NVML, NVAPI, AMD ADL, or load-based estimate
Memory	RAM % and Used GB	GlobalMemoryStatusEx
Disk	Activity % and Free Space	PDH PhysicalDisk(_Total) and GetDiskFreeSpaceExW
Battery	Charge % and AC status	GetSystemPowerStatus (hides automatically on AC-only desktops)
Uptime	System uptime	GetTickCount64

If a system lacks an exposed thermal sensor, the monitor shows a load-based temperature estimate prefixed with ~. This is an approximation, not a sensor reading. In System settings, optional local LibreHardwareMonitor support can read real CPU and GPU temperatures from its web server at http://127.0.0.1:8085/data.json when enabled in that tool. This does not start the server or require the tool for other metrics. LibreHardwareMonitor's server may listen on non-loopback interfaces; check its binding and firewall before enabling it.

Settings

Open the configuration window by double-clicking the tray icon or right-clicking and selecting Settings. You can also launch TaskbarMonitor.exe --settings to open it directly.

Metrics

Toggle metrics on or off. Set the target drive letter for storage monitoring and select network speed units (Bytes/s or Bits/s).

Position

• Alignment: Left, Right (tray adjacent), Center, or Custom.
• Coordinates: Horizontal offset, vertical offset, item gap spacing.
• Dividers: Toggle vertical lines between metric columns.

Text

• Font: Choose any installed Windows font.
• Size: 1 pt to 24 pt.
• Weight: Normal, Medium, Semi-Bold, or Bold.
• Preview: Shows the selected font with current CPU and memory readings before saving.

Colors

• Presets: Auto (matches Windows accent and dark/light mode), Dark, Light, or Custom.
• Custom colors: Independent color pickers for labels, values, upload, download, dividers, and background.
• Transparent background: Toggles window color-key transparency.
• Auto-contrast: Adjusts font luminosity when background contrast falls below readable thresholds.

System

• Polling Rate: Sensor refresh interval in milliseconds (minimum 100 ms, default 1000 ms).
• Settings Theme: Follow Windows, Dark Mode, or Light Mode.
• Autostart: Writes the executable path to the per-user Run key and checks whether Windows Startup Apps has disabled it. The Advanced tab shows the effective state. Enabling the option repairs a Windows-side disable, while unrelated settings changes leave an external disable untouched.
• Click-Through Mode: Sets WS_EX_TRANSPARENT so mouse clicks pass directly to the taskbar.
• Local Sensors: Optional LibreHardwareMonitor temperature source, using the local web endpoint on port 8085.

Tray Menu

Right-click the notification icon in the system tray:

• Settings: Opens configuration window.
• Open Task Manager: Runs taskmgr.exe.
• Refresh Theme: Re-reads Windows colors and redraws immediately.
• Click-Through Mode: Toggles mouse click pass-through.
• Exit Monitor: Closes the application.

Build Requirements

• Compiler: MinGW-w64 (GCC 10+) or MSVC (Visual Studio 2019+)
• Windows SDK
• C++17 support

Build with Batch File (MinGW)

Runs windres, builds TaskbarMonitor.exe with g++, and self-signs the binary:

build.bat

Build with Make

make

Build with CMake

mkdir build
cd build
cmake ..
cmake --build . --config Release

Linked System Libraries

• iphlpapi
• gdi32
• dwmapi
• pdh
• psapi
• shell32
• comctl32
• comdlg32
• ole32
• oleaut32
• wbemuuid

Optional Runtime Libraries

These are loaded dynamically via LoadLibraryW when present:

• nvml.dll: NVIDIA Management Library (temperature)
• nvapi64.dll or nvapi.dll: NVIDIA API fallback
• atiadlxx.dll or atiadlxy.dll: AMD Display Library (temperature)

If none are present and the optional local sensor feed is unavailable, temperature falls back to a load-based estimate marked with ~.

Configuration & Uninstallation

All settings are stored in the Windows Registry under: HKCU\Software\TaskbarMonitor

Autostart entry: HKCU\Software\Microsoft\Windows\CurrentVersion\Run\TaskbarMonitor

To uninstall, disable autostart in Settings, close the program, and delete the executable. No temporary files or background services are created.

When the application is launched manually, a startup prompt appears only when Windows startup is not effectively enabled. Launches from the startup entry do not show the prompt. Choosing Keep Disabled leaves the current Windows startup state unchanged.

License

MIT License. See src/License.cpp for details.